Chapter 1
1. c. Occupational injuries and illnesses are among the five leading causes of morbidity and mortality in the United States and in most other countries.
2. b. Occupational physicians play an important role in prevention, recognition, and treatment of injuries and illnesses.
3. c. The IME’s evaluation is often the highest level of evaluation the worker will encounter.
4. a. Board-certified physicians generally have more diverse practice activities and skills, with greater involvement in management, public health-oriented activities, and toxicology.
Chapter 2
1. c. Occupational health should have high priority on the international agenda, but occupational health and safety laws cover only about 10% of the population in developing countries.
2. d. The rise in migration for employment has had serious consequences for many countries. The most distinctive feature of these workers is their concentration in a few blue collar occupations—carpenters, masons, electricians, plumbers, truck drivers, mechanics, and heavy equipment operators.
3. c. Child labor is an economic and social reality in many developing countries. Children may provide 25% or more of a family’s total income, and many traditional cultures include child labor as an integral part of the child’s socialization and achievement of status in the local community. Governments may regard child labor as a key factor in keeping their economy competitive through the provision of cheap labor.
4. c. Globalization benefits countries that are competitive in the knowledge economy, which rewards skills and institutions that promote cutting-edge technological innovation, or the low-wage economy, which uses widely available technology to do routine tasks at the lowest possible cost. Middle-income countries have not done nearly as well under globalized markets as either richer or poorer countries.
5. b. The World Health Organization (WHO) is responsible for the technical aspects of occupational safety and health and the promotion of medical services and hygienic standards.
6. a. The WHO estimates that well over 100 million cases of occupational disease occur each year worldwide. Far too little effort is being made in the developing countries to prevent occupational disease.
7. c. The ILO is a tripartite organization of government, employer, and worker representatives that develops policy statements, conventions, recommendations, and guidelines through a consensus process that all agree are the “minimum standard” for occupational health and safety.
8. a. Occupational accidents cause permanent disabilities and economic losses amounting to 4–6% of national incomes. Well over two million people are killed by their work every year.
9. b. ILO conventions guide all countries in the promotion of workplace safety and in managing occupational health and safety programs. The ILO conventions and recommendations on occupational safety and health are international agreements that have legal force if they are ratified by the national parliament.
10. a. Agricultural work is the most prevalent type of employment in the world. In developing countries especially, the performance of the agricultural sector often depends on conditions outside policymakers’ reach.
11. d. Pesticides are essential to modern agriculture—more than 2 million tons of widely used pesticides in developing countries are highly toxic. Many of these pesticides are banned or severely restricted in developed countries, yet still legally sold to farmers in developing countries.
12. b. The construction industry accounts for around 7% of the world’s employment, but 30–40% of the world’s fatal injuries. Falls from heights due to inadequate scaffolding and lack of basic protections, being buried in excavations, or being crushed by vehicles or building materials are the most common causes of fatal injuries.
13. d. Regulation, Evaluation, and Authorization of Chemicals (REACH) restricts the use of carcinogens, mutagens, reproductive toxicants, and persistent and bioaccumulative substances. The Waste Electrical and Electronic Equipment (WEEE) Directive encourages the design and production of electronics equipment to facilitate dismantling and recovery, in particular the reuse and recycling of electronics equipment, components, and materials necessary to protect human health and the environment.
Chapter 3
1. a. The number of transnational migrants has more than doubled over the past 50 years.
2. b. The number of internal migrants, individuals who move within a country, far exceeds the global total of transnational migrants.
3. a. Immigrant workers are disproportionately congregated in high-risk occupations, where they are subject to hazards and exposures that can result in injury, illness, and death.
4. a. A migrant worker health profile can be used to alert staff to the unique health needs of the immigrant population.
5. d. Since immigrant workers are overrepresented in occupations where there are known illness and chronic disease risks, it is highly likely that immigrant workers suffer from more work-related health problems than native workers.
Chapter 4
1. a. Occupational/environmental history should include information about current and previous jobs in a systematic manner.
2. b. Safety data sheets provide information on the properties of hazardous chemicals and how they affect health and safety in the workplace.
3. d. SHE(O) may trigger regulatory or public health investigations that can lead to prompt control of new hazards.
Chapter 5
1. d. The electronic health record (EHR) allows access to parts of the record by the patient, so that the patient may serve as an active member of the health care team.
2. d. Some PHRs, specifically those that are not offered by HIPAA covered entities, may fall outside the scope of HIPAA protection.
3. a. Although the HIPAA privacy rule excludes employment records maintained by a health care organization in its capacity as an employer, there are federal acts and regulations that do guide the management of employee health records (ADA, FMLA, and OSHA).
4. b. National incentives, standards, and technical support are key factors that have helped promote the adoption of EHRs around the world.
Chapter 6
1. d. The employer is responsible for providing medical treatment and compensation benefits to the injured employee.
2. c. A work injury that activates or aggravates a preexisting condition is compensable. Recurrence of an earlier compensable injury is also compensable.
3. a. The vast majority of occupational injuries are minor in nature. Well over 90% of occupational injuries are temporary disability cases.
4. c. There is a waiting period for this type of compensation, but it is paid retroactively if the worker cannot work for a certain number of days or if hospitalization is necessary.
5. b. Permanent total disability covers workers who are so disabled that they will never be able to work again in an open labor market and for whom further treatment offers no hope of recovery.
6. d. Only the large employers are experience-rated. Small employers are typically insured in groups of similar companies.
7. b. Insurers in many states ask the physician to determine the degree of “impairment” (measured by anatomic or functional loss), which the insurers will give to disability raters, workers’ compensation judges, commissioners, or hearing officers.
8. c. Many states have rewritten their workers’ compensation laws, making it even more difficult for injured workers to receive compensation.
9. c. Apportionment applies only to permanent disability.
10. b. Compromise and release settlements are now accepted by workers’ compensation in nearly all states. These settlements allow the payment of benefits in a lump sum, rather than a series of payments over longer periods of eligibility. The settlement represents a compromise on the part of the claimant and the insurer or employer, although the settlement is more likely to benefit the employer or insurer in the long run. The agreements typically involve a partial or full release of the employer and insurer from further liability for the injury.
Chapter 7
1. d. A small but important group develop long-term work disability. Although these persons are just a few percent of all workers with health-related work limitations, they account for the majority of total days lost from work due to health conditions.
2. c. The two most widely used methods of determining functional capacity are performance-based tests, often using specific equipment and physical measurement instruments or job simulation, and self-assessments using questionnaires.
3. d. Vocational rehabilitation can address work instability and incongruity, where there may be a mismatch between the skill of the individual and the duties required by the job description.
4. c. A health risk appraisal or assessment (HRA) is a widely used screening tool that, through a self-report questionnaire, can obtain lifestyle data (like smoking, alcohol, and/or drug use), personal medical history (including prescription medication use), self-assessment of physical function (like hearing, vision, sleep, fatigue, depressive symptoms), and physiological data (like height and weight).
5. d. A comparative outcome study that examined a work-focused CBT intervention and a regular CBT intervention among employees on sick leave due to common mental disorders (including depression and anxiety) concludes that employees who received work-focused CBT resumed work earlier than those who received regular CBT.
6. c. Two methods to identify blue and black flags in the context of low back pain include: (1) using the clinical interview scenario or (2) using questionnaires, such as the Orebro Musculoskeletal Pain Questionnaire (OMPQ).
Chapter 8
1. a. Functional testing, including simple tasks performed during activities of daily living, is useful to assess injury severity.
2. a. CT scans are the most effective method for visualizing any bony pathology, including morphology of fractures.
3. b. Arthrocentesis must be performed promptly to rule out an infection when acute knee pain with effusion and inflammation are present and the patient is unable to actively flex the joint.
4. d. Cumulative trauma may involve the extremity (commonly the hand, wrist, elbow, or shoulder) or the trunk (low-back strain).
Chapter 9
1. a. The glenohumeral joint is surrounded by a fibrocartilagenous rim that helps to deepen and stabilize the joint. Tears that occur over the superior part of the labrum are known as “SLAP” lesions, or superior labral anterior to posterior lesions, and are often seen in throwing athletes such as pitchers.
2. a. Excessive force applied in any direction may cause a shoulder dislocation.
3. a. Acromioclavicular joint injuries may result from falls or from direct trauma to the arm or shoulder.
4. b. Thoracic outlet syndrome is a set of symptoms and signs caused by compression of the neurovascular structures passing out of the chest and neck and beneath the clavicle to the axilla.
5. c. Lateral humeral epicondylitis can occur among workers who perform repeated forceful pinching or power grasps.
6. d. Radial nerve entrapment at the elbow also called radial tunnel syndrome can be considered in cases of resistant lateral epicondylitis.
7. c. Compression of the nerve in the canal may be related to old elbow injuries with enlarging osteophytes, cubitus valgus, or subluxation of the nerve out of the groove.
8. d. De Quervain tenosynovitis involves the first dorsal compartment of the wrist. The onset is usually associated with overuse of the thumb and wrist particularly with radial deviation, as in repetitive hammering, lifting, or pipetting.
9. d. Stenosing tenosynovitis of the flexor tendon to a finger or of the flexor pollicis longus to the thumb may produce pain when the digit or thumb is forcibly flexed or extended.
10. d. Repeated or sustained forceful gripping or repetitive wrist and finger movements involved in work have been associated with carpal tunnel syndrome.
11. d. The diagnosis of carpal tunnel syndrome is confirmed by median nerve electrodiagnostic studies (nerve conduction studies and EMG).
12. c. Ulnar neuropathy at the wrist can be caused by a space-occupying lesion in the area of Guyon canal.
13. a. Hand arm vibration syndrome (HAVS) involves both neurologic and vascular signs and symptoms associated with the use of electric and pneumatic vibrating hand tools.
Chapter 10
1. b. Approximately 80% of episodes of low back pain resolve within 2 weeks and 90% resolve within 6 weeks.
2. d. Spinal stenosis may present with neurogenic claudication symptoms with walking.
3. d. The L5-S1 disk is affected in 90% of cases of lumbar disk herniation.
4. a. Hip fractures should be surgically repaired as soon as possible (within 24 hours).
5. c. Osteoarthritis involves a degeneration of the joint cartilage.
6. d. Anterior cruciate ligament injury leads to acute swelling immediately (or within 4 hours).
7. a. Collateral ligament injury is caused by a valgus or varus blow or stress to the knee.
8. a. Inversion ankle sprains may result in chronic instability.
Chapter 11
1. c. Pain has a felt, sensory quality and an affective aspect, demands our mind’s attention, and includes a strong behavioral drive toward homeostasis.
2. d. As pain persists, pain circuits develop a hypersensitive state, with pain itself being a pain predictive conditioning cue.
3. b. Opioid pain medications, in addition to their pain relief, particularly effective for acute pain, are both rewarding and behaviorally reinforcing.
4. a. Depression is more common in chronic pain patients than in healthy controls, and pain is more common in depressed patients than in nondepressed individuals.
5. c. Pharmacologic treatments for chronic pain are usually most effective when combined with other treatment strategies.
6. c. The goal of CBT is to help patients identify destructive thought patterns and learn to generate more constructive thought patterns.
7. a. Pacing techniques prevent these periods of over- or underactivity by teaching patients to measure out task in advance and plan the amount of time they intend to spend on an activity.
Chapter 12
1. a. Open-angle glaucoma accounts for most cases of glaucomatous visual loss (90%).
2. c. Visual fields should be tested, especially in patients with suspected head injury or a significant decrease in visual acuity.
3. b. Strong alkalis and acids can cause the most severe and damaging chemical injuries to the eye and eyelids.
4. a. Iridoplegia is caused by damage to the pupillary sphincter.
5. b. Secondary hemorrhage frequently continues until the anterior chamber is completely filled with blood, during which time the intraocular pressure may rise to 50–60 mm Hg (normal 12–20 mm Hg).
6. c. This radiation is generated by the welder’s arc and damages the exposed corneal and conjunctival epithelium.
7. d. Sympathetic ophthalmia can cause complete loss of vision in both eyes if unrecognized and untreated early in its course.
Chapter 13
1. d. In a clinical audiogram, conductive losses are indicated by an “air-bone gap,” in which the air-conduction threshold exceeds the bone-conduction threshold.
2. c. The speech reception threshold (SRT) is the intensity (in decibels) at which the listener is able to repeat 50% of balanced two-syllable words known as spondee words. The normal range for young adults is between 0 and 20 dB.
3. b. Tests like this are attractive because they use more realistic speech than conventional speech tests (sentences rather than isolated words) and incorporate background noise, which is important in some jobs.
4. d. ARHL has a large genetic component; heritability is close to 50%.
5. a. ISSHL is differentiated by its sudden onset, usually developing within 24 hours, in the absence of precipitating factors.
6. a. NIHL results mechanically from trauma to the sensory epithelium of the cochlea and metabolically from the generation of reactive oxygen species.
7. d. Because the acoustic reflex is neurally mediated, it is delayed in onset for a period ranging from 25 to 150 ms, depending on the intensity of the sound.
8. a. OSHA regulates exposure to noise at or above an 8-hour time-weighted average (TWA) of 85 dBA, the approximate biologic threshold above which permanent shifts in hearing are possible.
9. a. When 8-hour TWA noise levels are equal to or greater than 85 dBA (a 50% noise dose) but below 90 dBA (a 100% noise dose), HPDs must be made available to the exposed workers.
10. a. Ototoxic hearing loss is the result of exposure to chemical substances that injure the cochlea.
Chapter 14
1. a. Systemic hypothermia is reduction of the body’s core temperature below 35°C (95°F).
2. d. Heat stroke morbidity or mortality can result from cerebral, cardiovascular, hepatic, or renal damage.
3. c. A sudden exposure to intense electrical energy can cause not only tissue destruction and necrosis from heat and burning but also depolarization of electrically sensitive tissues such as nerve and heart.
4. d. Some patients with acute radiation syndrome pass through four phases: prodrome, latent phase, illness, and recovery.
5. d. Most cases of decompression sickness have occurred after rapid ascension from sea depths in excess of 9 m (29.5 ft) or after sudden cabin pressure loss at altitudes in excess of 7000 m (22,966 ft).
6. d. Class 3b and stronger lasers present two forms of risk: the power level can damage the eye before a blink reflex offers any protection, and even the diffuse reflection of an errant beam can cause eye damage.
7. c. High-pressure injection injuries often require extensive debridement with delayed closure.
Chapter 15
1. c. The head follows the visual target. Therefore, location of the visual target determines head rotation and flexion.
2. c. The risk-assessment tools like ACHIG TLV for HAL or the strain index estimate the risk for musculoskeletal disorders of the hand, wrist, forearm, and elbow.
3. d. The most important physical design rule for a sedentary job at a desk or workbench is that the operator be able to reach all frequently used items (e.g., parts, supplies, keyboards, tools, and controls) without leaning, bending, or twisting at the waist.
4. b. To avoid contact stress in the hands, tool handles should be designed so that the force-bearing area is as large as practicable and there are no sharp corners or edges.
5. a. Bifocal wearers will look at the screen through just the bottom of their glasses. Therefore, in order to prevent head extension, the screen should be lower than is usually recommended.
6. c. The NIOSH lifting equation aims to provide recommended weight limits (RWLs) that are protective of at least 75% of working women and 99% of working men.
7. a. The ACGIH TLV for lifting recommends upper limits for repetitive lifting, with the goal of allowing the majority of workers to perform the task without developing back and shoulder disorders.
8. a. HAVS involves damage to the small blood vessels and nerves of the fingers.
9. c. The maximum lift allowable by the NIOSH lifting equation is 51 lb.
10. a. Primary visual targets (screens and hard copy) should be located in front of the operator, between 0 and 30 degrees below eye level, and approximately 48–72 cm (20–30 in) away.
11. c. Repeated grip forces of greater than 10 N (1 kg) are associated with a greater risk of carpal tunnel syndrome.
12. d. Women of average dimensions (50th percentile) can reach horizontally only about 74 cm (29 in), and short women (5th percentile) can reach horizontally only about 68 cm (27 in), as measured from the backrest of the chair when they are seated in an upright position.
Chapter 16
1. a. Nanoparticles are engineered structures that are less than 100 nm in size.
2. d. Toxicity is affected by atmospheric pressure, temperature, and humidity.
3. b. G6PD deficiency is an X-linked recessive disorder.
4. a. Biotransformation occurs in the liver by hydrolysis, oxidation, reduction, and conjugation.
5. d. Clearance is a measure not of how many milligrams of toxin is being removed but rather of the volume of fluid that is freed of the toxic agent per unit of time.
6. d. The results of hair analysis are difficult to interpret as hair samples are subject to external contamination.
7. a. Management of acute toxicity consists of removal from exposure, symptomatic treatment, and supportive care.
Chapter 17
1. c. Lymphocytes are responsible for the initial specific recognition of antigen.
2. b. Cytotoxic or “killer” T cells are responsible for defense against intracellular pathogens (eg, viruses), tumor immunity, and organ graft rejection.
3. c. Macrophages are involved in the ingestion, processing, and presentation of antigens for interaction with lymphocytes.
4. a. Eosinophils play both a proactive and a modulating role in inflammation.
5. a. Type I anaphylactic or immediate hypersensitivity reactions are initiated by the interaction of antigen with specific IgE antibodies bound to mast cells and basophils with the subsequent release of inflammatory mediators.
6. b. Reactive airways dysfunction syndrome (RADS) is a syndrome characterized by the acute emergence of bronchial hyperreactivity and symptoms of asthma, after an acute exposure to high levels of respiratory irritants, usually toxic chemicals, smoke, or particulates.
7. d. Allergic contact dermatitis (ACD) is a type IV delayed hypersensitivity disorder, caused by a variety of agents in the occupational setting including latex, nickel, formaldehyde, potassium dichromate, thiurams, epoxy resins, mercaptos, parabens, quaternium-15, ethylenediamine, and cobalt.
8. a. The late-reacting systemic syndrome (“TMA flu”) is characterized by cough, occasional wheezing, dyspnea, and systemic symptoms of malaise, chills, myalgia, and arthralgia.
9. b. Patch tests are useful in evaluating skin contact sensitivity (type IV delayed hypersensitivity).
10. a. Inhalation challenge tests are conducted by exposing the worker to the suspected antigen.
Chapter 18
1. d. Methemoglobin is dangerous because of its inability to bind oxygen and because it increases the oxygen affinity of the remaining heme groups in hemoglobin tetramer, thereby decreasing oxygen delivery to the tissues.
2. d. Clinically, symptomatic porphyria can occur either as a result of inadequate enzymatic function along any step in heme biosynthesis or as a result of inappropriate overstimulation of δ-aminolevulinic acid synthetase, usually in the setting of decreased heme concentration.
3. c. The major differences between the two diseases are (1) an increase in neuropsychiatric signs in acute intermittent porphyria compared with lead intoxication and (2) anemia, which is present in lead intoxication but virtually absent in porphyria.
4. c. Aplastic anemia, or medullary aplasia, is an acquired abnormality of the pluripotent hematopoietic stem cells resulting in pancytopenia (anemia, neutropenia, and thrombocytopenia).
5. b. The myelodysplastic syndromes are a group of acquired genetic disorders of the blood-forming cells similar to cancer and characterized by ineffective hematopoiesis, clinically resulting in anemia, neutropenia, thrombocytopenia, or a combination of cytopenias.
6. c. Multiple myeloma is characterized by anemia, painful lytic and osteopenic bone disease, monoclonal immunoglobulin production (in serum or urine or both), hypogammaglobulinemia, and short survival.
Chapter 19
1. c. In both experimental animal models of cancer and human cancers with known causes, a significant interval of time is required from first exposure to the responsible agent to the development of malignancy. This interval is referred to as theinduction-latency (or sometimes just latency) or incubation period.
2. a. Epidemiologic studies provide the strongest evidence for human carcinogenicity.
3. d. One of the best-studied and most commonly performed short-term tests is the Ames test, which uses a mutant strain of Salmonella typhimurium that is deficient in the enzymes required to synthesize histidine and which will not grow unless histidine is added to the growth medium.
4. a. Tests for DNA repair can demonstrate that DNA damage has occurred following exposure to a chemical.
5. a. DNA or protein adducts are a potentially valuable tool in the measurement of levels of specific carcinogens covalently bound to DNA or proteins.
6. c. Lung cancer is a major asbestos-related disease, accounting for 20% of all deaths in asbestos-exposed cohorts.
7. d. Diesel-engine exhaust contains a number of nitroarenes, which are nitro-substituted derivatives of polycyclic aromatic hydrocarbons (arenes).
8. d. Many different occupational exposures are linked to cancer of the nasal cavity and paranasal sinuses.
9. d. NIOSH has concluded that all benzidine-derived dyes should be considered to be potential human carcinogens.
10. d. Skin cancers from arsenic exposure tend to be multiple and occur in younger patients than those attributable to UV light.
11. b. The two major forms of leukemia that have been linked to occupation are acute nonlymphocytic leukemia (ANLL)—including myelodysplasia and preleukemia—and chronic myelogenous leukemia (CML).
Chapter 20
1. c. MERS is caused by a coronavirus.
2. d. The African region has approximately one quarter of the world’s cases, and the highest rates of cases and deaths relative to population.
3. d. The TST test is considered positive in high-risk occupational groups with a reaction of 10 mm or more.
4. d. Transmission following mucous membrane exposure is rare, with no apparent transfer following exposures to intact skin.
5. a. Hepatitis A is a viral hepatitis transmitted through the fecal-oral route.
6. a. Occupational brucellosis infection is systemic and may result in gastric, intestinal, neurologic, hepatic, or musculoskeletal involvement.
Chapter 21
1. a. Irritant contact dermatitis is a common form of occupational skin disease and, in the United States, accounts for nearly 80% of all occupational dermatitis.
2. d. ICD is a nonimmunogenic skin reaction to toxic substances either in low or high concentrations.
3. b. Numerous systemic drugs can cause phototoxic reactions.
4. c. The initial site of leukoderma is usually the hands and forearms.
5. d. ACD is an immunologic reaction classified as a delayed type IV or cell-mediated hypersensitivity. This distinguishes it from type I reactions, which are immediate and antibody mediated.
6. c. ACD results in considerable variation in the intensity of reaction depending on the body area affected.
7. a. ACD sensitization requires at least 4 days to develop.
8. a. The key to diagnosis of allergic contact dermatitis is diagnostic patch testing.
9. b. Photoallergic reactions are immunologically based.
10. b. With sufficient provocation, nearly all exposed individuals will develop nonallergic contact urticaria. Previous sensitization is not necessary.
11. c. Allergic contact urticaria reactions are immunoglobulin E (IgE)–mediated type I immediate hypersensitivity reactions and appear to be more common in atopics.
12. d. Peripheral neuritis and hepatotoxicity may occur with chloracne, suggesting systemic toxicity.
13. d. Employment of persons with active atopic dermatitis in food service industries and hospital patient care may need to be restricted.
14. c. Treatment of atypical mycobacterial infections with rifampicin or ethambutol is usually effective.
15. a. Avoidance, substitution with less-allergenic chemicals, modification of work activities and protective measures are the best approach to management.
16. c. Prevention of occupational skin disorders requires close cooperation between the employee, employers, company physicians, dermatologists, and other relevant stakeholders such as workers unions.
Chapter 22
1. b. A growing body of evidence links the development of rhinitis with that of asthma, making the prevention (and early recognition) of upper airway inflammation a priority.
2. d. Workplace allergens producing allergic rhinitis may be either commonly encountered allergens, exposure to which may be incidental to the work environment (eg, grass pollen exposure in a landscaping gardener), or unusual agents encountered only in industrial environments (eg, trimellitic anhydride exposure in a plastics worker).
3. c. High-grade nasal obstruction (a reflex response to irritants and allergens) predisposes to oral breathing, bypassing the filtration and air-conditioning functions of the upper airway. This may be one of the mechanisms whereby rhinitis and asthma severity are linked.
4. d. Nasal hyperreativity is a defining characteristic of vasomotor rhinitis, but can also be found in a subset (~40%) of allergic rhinitics.
5. a. Sinusitis has been linked to asthma incidence and severity.
Chapter 23
1. b. The diffusing capacity of the lung for carbon monoxide (DLCO) is closely correlated with the capacity of the lungs to absorb oxygen.
2. a. Bronchoprovocation tests are useful in the diagnosis of occupational asthma.
3. b. The site of deposition of an inhaled gas is determined primarily by water solubility.
4. a. Occupational asthma caused by such diverse agents as diisocyanates, snow crab, and western red cedar show persistence of symptoms and the presence of nonspecific airway hyperresponsiveness for periods up to 6 years after removal from the offending agent.
5. c. Hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis, refers to an immunologically mediated inflammatory disease of the lung parenchyma that is induced by inhalation of organic dusts that contain a variety of etiologic agents (eg, bacteria, fungi, amoebae, animal proteins, and several low-molecular-weight chemicals).
6. b. Silicosis is a parenchymal lung disease that results from the inhalation of silicon dioxide, or silica, in crystalline form.
7. c. Coal workers’ pneumoconiosis may lead to progressive massive fibrosis, identical to that of silicosis.
8. a. In reflex bronchoconstriction, neuroreceptors in the airway are stimulated by agents such as cold air, dusts, mists, vapors, and fumes.
Chapter 24
1. a. Chronic exposure to carbon disulfide appears to accelerate atherosclerosis and/or precipitate acute coronary ischemic events.
2. d. Carbon monoxide exposure may aggravate or induce cardiac arrhythmias.
3. d. Case-control studies suggest a 2.5- to 4-fold increase in the risk of cardiovascular death in workers handling explosives.
4. a. Intoxication with organophosphate and carba-mate insecticides can produce diverse cardiovascular disturbances, including tachycardia and hypertension, bradycardia and hypotension, heart block, and ventricular tachycardia.
5. a. Arsine gas causes red blood cell hemolysis.
Chapter 25
1. a. Direct hepatotoxins or their metabolic products injure the hepatocyte and its organelles by a direct physicochemical effect, such as peroxidation of membrane lipids, denaturation of proteins, or other chemical changes that lead to destruction or distortion of cell membranes.
2. a. Indirect hepatotoxins are antimetabolites and related compounds that produce hepatic injury by interference with metabolic pathways.
3. b. The strategic role of the liver as the primary defense against xenobiotics depends largely on cellular enzyme systems (mixed-function oxidases [MFOs]).
4. d. Renal failure may ensue a few days after the carbon tetrachloride hepatic damage becomes manifest and in fact has been the cause of death in most fatal cases.
5. b. TASH has recently been used to describe hepatic steatosis, inflammation, and fibrosis among vinyl chloride production workers.
6. a. While contaminated food and water are common epidemic sources, hepatitis A is transmitted primarily by person-to-person contact, generally through fecal contamination.
7. b. Transmission occurs via percutaneous or permucosal routes when exposure to blood or potentially infectious body fluids occurs; HBV is not transmitted via the fecal-oral route or by contamination of food or water.
8. c. HCV is spread primarily through parenteral exposures from blood transfusions or intravenous drug abuse.
9. c. In the occupational setting, measures of hepatic functional capacity have been used epidemiologically to demonstrate liver dysfunction in the absence of clinical or serologic abnormalities.
10. a. The use of Cytokeratin 18 (CK18) has recently been explored as a tool to assess occupational liver disease.
Chapter 26
1. a. The kidney is especially vulnerable to occupational and environmental exposures.
2. d. In acute kidney injury, patients may require dialysis until the renal function recovers.
3. d. Most chronic kidney diseases associated with exposure to agents such as lead or cadmium present with chronic interstitial nephritis characterized by tubular proteinuria (usually <2 g/24 h) and a urine sediment usually lacking any cellular elements.
4. a. Balkan-endemic nephropathy (BEN) is now considered a form of aristolochic acid nephropathy.
5. c. Lead nephropathy renal ultrasonography typically shows small, contracted kidneys.
6. a. Overt lead nephropathy is one of the few preventable renal diseases.
7. b. Once a critical concentration of 200 μg/g of renal cortex is achieved, the renal effects of cadmium, such as Fanconi syndrome, become evident.
8. a. Heavy exposure to silica can result in a generalized systemic disease resembling collagen-vascular disease, such as systemic lupus erythematosus.
9. c. The cause of the epidemic of chronic kidney disease in Central America is unknown. It disproportionately affects agricultural workers at lower, warm weather altitudes.
10. c. Toluene inhalation (glue sniffing) is a classic cause of distal renal tubular acidosis.
Chapter 27
1. c. Encephalopathy is a general term that denotes a diffuse dysfunction of the central nervous system. The clinical manifestations may be diverse. Depressed level of consciousness is common, as are cognitive and psychiatric symptoms. Other manifestations depend on the selectivity of the injury. For instance, some toxins may cause more selective injury to the vestibular system or cerebellum resulting in dysequilibrium, vertigo, and gait or limb ataxia. Others may affect the basal ganglia causing an extrapyramidal syndrome of bradykinesia, tremors, and rigidity.
2. a. Evaluation of cognitive complaints should include at least a mini–mental state examination.
3. b. Peripheral nervous system disorders lead to sensory disturbances and weakness, often accompanied by impairment of the deep tendon reflexes on physical examination.
4. c. The hallmark of most polyneuropathies is the distal distribution of the clinical symptoms and signs.
5. c. Peripheral neuropathy may result from a wide range of systemic conditions. Despite continuing advances, the causes of many neuropathies remain elusive despite testing.
6. a. Focal neuropathy is a condition in which a single nerve is affected. Symptoms arise from the motor and sensory fibers in the affected nerve, typically resulting in weakness and sensory loss in a restricted anatomic distribution.
7. c. A neuropathy may develop as a delayed manifestation a few weeks after acute acrylamide exposure or insidiously after chronic exposure.
8. d. Chronic exposure leads to a more insidious sensorimotor polyneuropathy, although there is no agreement for a threshold limit.
9. a. Like many other toxins, mercury poisoning causes a diffuse encephalopathy.
10. b. Severe organophosphate intoxication may cause convulsions, coma, muscle paralysis, and respiratory arrest occur with severe intoxication.
Chapter 28
1. a. Chemical exposures during weeks 1 and 2 after conception may cause early pregnancy loss if they interfere with tubal transport, implantation, or endocrine control or if they are cytotoxic to the fetus itself.
2. c. Chemical exposures after the first trimester may induce minor morphologic abnormalities or growth deficits.
3. b. Endocrine-disrupting chemicals are hormonally active agents.
4. c. Solvents such as perchloroethylene, methylene chloride, toluene, xylene, and glycol ethers have been associated with concurrent elevation in SAB risk.
5. d. Tobacco smoking is associated with infertility, menstrual disorders, and menopause at earlier age.
Chapter 29
1. d. Semen abnormalities can include azoospermia (complete absence of sperm), oligospermia (decreased sperm count), teratospermia (abnormally shaped sperm), and asthenospermia (sperm showing decreased motility).
2. d. Most occupational events involving high-level exposures and documented adverse reproductive effects have occurred in male workers with exposure to DBCP and exogenous estrogens.
3. d. Decreased fertility was experienced among workers with testicular changes, and the most extreme FSH elevations were found in workers who did not recover after a period of no exposure.
4. c. Inorganic lead presents in some males as endocrine changes (decreased testosterone and increased LH levels).
5. d. Phthalates may cause human male reproductive damage at levels found in the general population.
Chapter 30
1. d. Chronic arsenic inhalation may cause lung cancer, and chronic arsenic ingestion may cause cancer of the skin, lung, and bladder.
2. b. Chronic berylliosis may develop after months or years of exposure or following a single acute exposure.
3. a. The beryllium lymphocyte proliferation test (BeLPT) confirms sensitization.
4. c. Renal tubular dysfunction resulting from chronic exposure to cadmium can result in nephrolithiasis and osteomalacia.
5. c. Cough, chest pain, and dyspnea may indicate exposure to irritant levels of soluble chromium compounds or the development of chromium-induced asthma.
6. a. Acute high-dose lead exposure may induce a hemolytic anemia (or anemia with basophilic stippling if exposure has been subacute).
7. c. Approximately 95% of all elevated blood lead levels among adults in the Untied States are work related.
8. d. In 2010, the CDC issued guidelines recommending medical removal from workplace exposure of any woman with a prenatal blood lead level of equal to or greater than 10 µg/dL.
9. c. Exposure to manganese may lead to a clinical syndrome that is similar to idiopathic parkinsonism, with slow speech, masked facies, bradykinesia, gait dysfunction, and micrographia.
10. d. The release of mercury into the atmosphere from both natural sources, such as volcanoes, and industrial emissions has led to global distribution of this element.
11. b. Nickel is a common cause of allergic contact dermatitis.
Chapter 31
1. a. Hydrofluoric acid (hydrogen fluoride) occupational exposure can occur both by direct skin contact and by inhalation of fumes.
2. d. Formaldehyde is a by-product of the incomplete combustion of hydrocarbons and is found in small amounts in automobile exhaust and cigarette smoke.
3. a. Symptoms of acute nitroglycerine illness include loss of consciousness, severe headache, difficulty breathing, weak pulse, and pallor.
4. a. PCP is used as a wood preservative, herbicide, defoliant, and fungicide.
5. c. PCBs have an efficient transplacental transfer, and adverse reproductive effects of PCBs have been reported in many animal species.
6. b. Styrene chronic exposure may cause weakness, headache, fatigue, poor memory, and dizziness.
7. a. Vinyl chloride disease is a syndrome consisting of Raynaud phenomenon, acroosteolysis, joint and muscle pain, enhanced collagen deposition, stiffness of the hands, and scleroderma-like skin changes.
Chapter 32
1. c. Solvents may be classified as aqueous (water-based) or organic (hydrocarbon-based).
2. b. Skin absorption rates vary widely among individuals by at least a factor of 4.
3. a. One isomer of hexane, n-hexane, causes peripheral neuropathy.
4. d. Aromatic hydrocarbons cause acute anesthetic effects, respiratory tract irritation, and dermatitis and are associated with neurobehavioral dysfunction.
5. c. Respiratory tract and eye irritation usually occurs at lower concentrations than central nervous system depression and thus serves as a useful warning property.
6. c. Methylene chloride is unique in that it is metabolized to carbon monoxide, with formation of carboxyhemoglobin.
Chapter 33
1. a. High-intensity exposure to toxic gases and other airborne toxicants may result in clinical findings within seconds, minutes, or hours.
2. d. Simple asphyxiants include methane gas, argon, carbon dioxide, and nitrogen.
3. c. Methane is also released in coal and other fossil fuel extraction settings and in the presence of organic material breakdown (including landfills).
4. d. Although carbon dioxide is considered a simple asphyxiant, at high concentrations it also acts as a potent central nervous system depressant.
5. a. Carbon monoxide competes with oxygen for binding sites on hemoglobin, thereby reducing the oxygen-carrying capacity of the blood.
6. a. Major current industrial use of cyanide is in metal plating operations and in the extraction of silver and gold salts from ores.
7. a. Like cyanide, hydrogen sulfide exerts its toxicity by blocking oxygen utilization through the cytochrome oxidase pathway.
8. d. Clinical findings in smoke inhalation injury can include features of both asphyxiant and irritant injury.
9. a. Preformed arsine gas, often stored under pressure in large quantities, is used as a dopant in the microelectronics industry.
10. d. With lower-level exposure of phosphine gas, pulmonary toxicity may be the primary manifestation, marked by dyspnea, cough, chest pain, and delayed-onset pulmonary edema in the hours following the exposure.
Chapter 34
1. a. In the United States, the Environmental Protection Agency (EPA) regulates the registration, sale, and conditions of use of all pesticides.
2. b. Organophosphates potency depends on their ability to bind with the cholinesterase molecule.
3. c. Carbamates differ from organophosphates in causing reversible rather than irreversible cholinesterase inhibition and typically have a short clinical course.
4. d. The initial diagnosis can be made on clinical grounds alone, samples sent to the laboratory, and a test dose of atro-pine delivered. A dose of atropine sulfate produces signs of mild atropinization in a normal adult; it has no effect in an individual with organophosphate poisoning.
5. d. The organochlorines are highly fat soluble and are distributed to adipose tissue, the liver, and the nervous system.
6. a. The fumigants have in common innately high vapor pressures or by-products with high vapor pressure.
7. d. The halogenated hydrocarbon fumigants share many of the effects of the halogenated hydrocarbon solvents, includ ing cardiac sensitization, direct cellular toxicity to the liver and kidneys, and carcinogenicity in laboratory animals.
Chapter 35
1. d. The hallmark of major depression is a severely depressed mood lasting at least 2 weeks.
2. a. Bipolar disorder is a cyclical mood disorder involving at least one episode of abnormally elevated energy level and mood which usually alternate with one or more episodes of depression.
3. c. The majority of individuals subject to shiftwork or jet travel–related time shifts in their sleep-wake schedules commonly report some degree of depressive symptoms.
4. b. Extensive disruption in circadian function is known to occur among patients with bipolar disorder.
5. a. Determining whether or not an employee may become violent has less to do with a static profile of that person than a series of dynamic variables (behaviors).
Chapter 36
1. a. Substance use disorders usually are accompanied by a decline in social and occupational functioning, making the workplace a good place to observe this decline in an individual’s functioning and to direct the worker to appropriate treatment.
2. d. The basic criteria for a substance use disorder diagnosis include tolerance; withdrawal; craving or urge to use; failure to fulfill major obligations at work, school, and home; and compulsive use despite serious issues created by substance use.
3. b. Alcoholism is by far the most serious chemical dependency problem encountered in the workplace.
4. c. The CAGE questionnaire is a highly effective tool in establishing a diagnosis of alcohol use disorder.
5. c. Tetrahydrocannabinol (THC), the active ingredient of cannabis, creates a feeling of euphoria and relaxation, but also causes impairment in judgment and motor coordination.
6. a. Cannabis is the substance most commonly detected in workplace urine testing.
7. c. Cocaine produces an intense adrenergic discharge, resulting in tachycardia, hypertension, and mydriasis.
8. c. Amphetamine withdrawal symptoms include dysphoria, irritability, extreme fatigue, psychomotor agitation, increased appetite, and vivid dreams.
9. a. Opioids produce profound mental and psychomotor slowing that will interfere with almost any work task.
Chapter 37
1. b. Nerve agent ocular effects include miosis, lacrimation, conjunctival injection, pain, and blurred or dim vision.
2. b. Mustard is a highly reactive molecule and acts as an alkylating agent to cause cellular tissue damage.
3. a. Anthrax is an infectious disease that affects animals and humans.
4. a. Inhalational anthrax begins with nonspecific symptoms of malaise, fatigue, myalgia, and fever.
5. a. Cutaneous anthrax first appears as a small papule that progresses to a vesicle containing serosanguinous fluid.
6. b. Gastrointestinal anthrax presents with nonspecific symptoms of nausea, vomiting, and fever.
7. d. Botulinum toxin attacks the presynaptic terminal of the peripheral nerves blocking the release of acetylcho-line and inhibiting muscle contraction.
8. c. Ricin is a cellular toxin that inhibits protein synthesis by binding to and catalytically modifying ribosomes.
9. d. After inhalation of ricin, hemoptysis and pulmonary edema may develop over the next 18–36 hours leading to respiratory failure and death.
Chapter 38
1. c. Certified Safety Professional (CSP) is the highest professional designation recognized by the BCSP.
2. b. The safety and health management system guides the organization to (1) prevent work-related injuries and illnesses, (2) comply with applicable health and safety regulations, and (3) minimize injury/illness, regulatory, and related compliance costs and violations.
3. a. Injury and Illness Prevention (IIP) programs are universal interventions that can substantially reduce the number and severity of workplace injuries and alleviate the associated financial burdens on workplaces.
4. c. Hazard assessment procedures should be part of an effective IIP program.
5. a. A hazard can cause harm or adverse effects to individuals as health effects or to organizations as property or equipment losses.
6. a. OSHA and often other regulatory agencies require employers in nearly all cases to prepare and implement an EAP for emergency situations.
7. b. All employers with hazardous chemicals in their workplaces must have labels and safety data sheets for their exposed workers, and train them to handle the chemicals safely and appropriately.
8. d. Exposure records consist of safety and/or industrial hygiene air and exposure monitoring data, and biological monitoring data.
9. b. Hazard prevention and control ensures that hazard correction procedures are in place.
10. b. Job safety analysis (JSA) uncovers the inherent hazards in the work environment, a task or activity, and recommends control strategies.
Chapter 39
1. a. The walk-through survey is the first and most important technique used to recognize occupational health hazards.
2. d. The current OSHA Workers’ Right-to-Know regulation makes explicit (and subject to governmental investigation) the commonsense duty of the employer to inform workers of the nature and hazards of materials to which they may be exposed.
3. b. Sampling and analysis of airborne contaminants is a definitive function of the industrial hygienist.
4. d. Phase-contrast microscopy gives an imperfect index of exposure to all asbestos fibers.
5. c. Wipe sampling may be a useful adjunct to programs used to evaluate the effectiveness of housekeeping measures, particularly in manufacturing facilities where separation of manufacturing areas from cafeterias, offices, or dressing rooms is important.
6. b. Sound-level meters typically contain filtering circuits that permit evaluation of exposures to components of the noise spectrum weighted in accordance with their effects on hearing.
7. a. TLVs—or the OSHA PELs and the NIOSH RELs—represent maximum allowable time-weighted exposure levels.
Chapter 40
1. a. Public health surveillance systems seek to assess the burden and distribution of occupational diseases in the population.
2. d. To address the lack of uniformity in coding, a large collaborative initiative established a number of programs aimed at the standardization and routine recording of industry and occupation on death certificates.
3. b. The National Health and Nutrition Examination Survey (NHANES) is a program of studies of children and adults whose primary purpose is to assess the health and nutrition status of US residents.
4. d. The CDC administers the National Program of Cancer Registries (NPCR), which supports central cancer registries in 45 states representing 96% of the US population.
5. d. Even for injuries, there is concern that the SOII substantially undercounts work-related events.
Chapter 41
1. c. Medical surveillance entails compiling and analyzing the health data from workers over a period of time.
2. d. Medical surveillance is the process of identifying, quantifying, and removing causative factors that increase the risk of occupational diseases or injuries.
3. a. Primary prevention methods are intended to minimize employee exposure to hazards and risk of injury or occupational disease.
4. d. Health-based regulations apply to hazardous substances such as lead, asbestos, and benzene.
5. c. The compliance plan must be reviewed and reevaluated at regular intervals at least annually.
6. b. Action level (AL) initiates medical surveillance.
7. d. OSHA health standards are codified as regulations such that employers may assume that all doctors are trained and knowledgeable for any problem or service that they or their facility offers.
8. d. The physician has a duty to protect confidential information learned about the company and its processes and methods. Usually this information is protected in a contractual agreement between the employer and the physician or medical practice.
9. d. OSHA health standards only require that physicians evaluate health effects and risks of employees on an individual basis, not as a group.
10. c. Temporary removal of an employee from an exposure can be based upon the physician’s assessment of the employee’s medical condition which places the employee at increased risk of adverse health effects resulting from exposure.
Chapter 42
1. b. Biologic markers or biomarkers are indicators of biochemical, genetic, molecular, immunologic, or physiologic signals of events in biologic systems.
2. d. Blood can be a valuable matrix for measuring adducts of hemoglobin, albumin, or DNA.
3. c. Measurements of chemicals in exhaled air include the measurement of exhaled nitric oxide (NO), a well-known method to assess airway inflammation.
4. c. Health-based values may incorporate safety factors.
5. b. BEIs are based on a critical evaluation of the literature and studies submitted for review, with an emphasis on studies that address minimal or no adverse health effect levels in exposed workers and animals.
6. a. Biologic monitoring in the occupational setting may be a voluntary or required component of routine medical surveillance as well as worker monitoring during and after emergency response.
Chapter 43
1. a. Global oil consumption reached 88 million barrels per day in 2011, which accounts for 33.1% of global energy consumption.
2. a. Transportation, which relies almost exclusively on oil, accounts for nearly 30% of US energy demand and 20% of US emissions of carbon dioxide.
3. c. Dioxins are not produced intentionally, but are byproducts of incineration, combustion, chlorine-based bleaching, and other industrial processes. Dioxins are known human carcinogens and are well-established endocrine disruptors.
4. d. Prenatal phthalate exposure has been associated with testicular dysgenesis syndrome, an entity first described in 2001 is a result of disrupted gonadal development during fetal life, resulting in poor semen quality and higher rates of undescended testis, hypospadias, and testicular cancer.
5. c. Although the DBCP and vinyl chloride cancer clusters in workers were the first evidence in humans, both of these clusters were preceded (in some cases over a decade earlier) by significant evidence from animal toxicology tests of male infertility and liver cancer, respectively. The link between diacetyl (artificial butter flavoring) and bronchiolitis obliterans was first identified in the workplace. The disaster in Minamata, Japan involved methyl (organic) mercury poisoning.
6. d. Risks tend to be perceived as more serious if they are outside individual control, less familiar, and linked to a dreaded disease and affect children. If the benefit is seen as going to a distant corporation rather than a local and familiar company, the risks also tend to be seen as more serious.
7. d. The Institute of Medicine’s consensus report, “Toward Environmental Justice: Research, Education, and Health Policy Needs,” recommended environmental education relevant to environmental justice for all health professionals. Environmental justice is a social movement that is based on empirical evidence and that is very relevant to health providers because it relates to health disparities and to risk communication.
8. b. Health care providers should be familiar with some basic information about the region in which they practice, including whether background levels of naturally-occurring radon may be elevated, so they can recommend that people get their homes tested; local sources of drinking water and local industries and pesticide use are also relevant factors to be familiar with in order to better diagnose potential occupational or environmental disease, to inform patients, and to respond quickly in the event of an incident. Health providers should also consider subscribing to an air quality alert (via email, text, or an App) so they know when air pollution levels are dangerously high. Although clinicians should recommend that patients have carbon monoxide detectors in their homes, they do not need to keep track of which homes have them.
Chapter 44
1. a. UN declarations, while not carrying the force of law, nevertheless articulate important and widely recognized principles for preventing occupational and environmental disease.
2. c. REACH shifts the burden for providing hazard information and for ensuring safety from public agencies to chemical producers.
3. d. REACH carries the force of law.
Chapter 45
1. c. CAPs include chemicals emitted in large quantities and from many sources such as carbon monoxide (CO), sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter (<10 and 2.5 µm in diameter, or PM10 and PM2.5).
2. c. The united States maintains a list of chemicals that have been formally identified as HAPs.
3. d. Superfund Amendments and Reauthorization Act (SARA) mandates emergency planning for chemical accidents.
4. d. Exposure to HAPs may contribute to respiratory disease, systemic toxicity, and carcinogenicity.
5. d. The Clean Air Act provides for use of market-based principles and other innovative approaches to reduce air pollution.
6. b. Many local jurisdictions have developed hazardous materials (HAZMAT) teams, trained to identify and respond to hazardous materials incidents.
7. a. Emergency response action levels are used to guide shelter-in-place or evacuation decisions; if evacuation has occurred, these levels may be used to determine when it is safe for community members to reenter the area.
8. a. The EPA has developed a system of protective action guides (PAGs) to help officials make critical decisions following a nuclear accident.
9. c. Hazardous waste exclusions include agricultural wastes used as fertilizers.
10. b. ATSDR has developed several specialized registries to study the long-term health effects of exposure to specific chemicals at hazardous waste sites, with the intention of combining data from several sites where similar exposures have occurred to achieve populations large enough that the associated health effects can be detected.
Chapter 46
1. d. The Clean Air Act (CAA) is the principal federal standard addressing outdoor air quality in the United States.
2. d. The CAA mandates that the primary NAAQS be set to protect the health of all sensitive groups within the population.
3. a. Stationary sources of air pollution are primarily power or manufacturing plants and are responsible for most sulfur dioxide (SO2) emissions, as well as considerable amounts of nitrogen oxides (NOx) and particulate matter.
4. a. Ozone is a colorless, pungent, relatively water-insoluble gas.
5. a. In contrast to other criteria pollutants, NO2 is a common contaminant of indoor air, and indoor levels often exceed those found outdoors.
6. c. Sulfur dioxide leads to the secondary formation of acid aerosols.
7. b. Because CO has no direct effect on the lungs, its principal adverse health effects are through its ability to cause or exacerbate diseases associated with impaired oxygen delivery.
Chapter 47
1. d. Short-latency illnesses are characterized by a relatively acute onset, closely related in time to the individual’s presence within the building and often relieved by removal from further exposure.
2. a. Long-latency illnesses include cancer and chronic pulmonary diseases, perhaps resulting from long-term low-level exposure to contaminants in indoor air.
3. b. The term sick-building syndrome (SBS; previously referred to as closed-building syndrome or tight-building syndrome and sometimes referred to as nonspecific building-associated illness) denotes a characteristic set of symptoms, typically headache and mucous membrane irritation, recognized among occupants of nonindustrial buildings such as offices and schools.
4. b. Mass psychogenic (or sociogenic) illness is an illness of psychophysiologic origin occurring simultaneously in a group of individuals.
5. d. Carbon monoxide in buildings may be entrained from the outside via air intakes in the vicinity of vehicle loading docks.
Chapter 48
1. b. Unless otherwise stated, BOD signifies the biochemical oxygen demand for 5 days at 20°C (68°F).
2. b. COD determines the quantity of oxidizable material in the water.
3. a. During hydraulic fracturing (fracking), a fluid mixture is pumped deep underground where it fractures the rock to liberate trapped natural gas. Fracking fluids amount to between 2 and 7 million gallons of water per well.
4. c. The Safe Drinking Water Act authorizes the U.S. EPA to establish and enforce regulations for chemicals and other toxic agents in drinking water.
5. b. The U.S. EPA sets two standards for each regulated pollutant. The first standard, called a maximum contaminant level goal (MCLG), is set at a concentration that is not expected to cause adverse health effects over a lifetime of consumption of water at that concentration. A substantial safety margin for this MCLG is included in each unenforceable standard.
6. b. The most common disinfection by-products are trihalomethanes and haloacetic acids and some studies have linked these to cancer.
Chapter 49
1. d. Symptoms of MCS resemble those of sick-building syndrome, a constellation of excessive work-related symptoms related to an indoor office environment (eg, headache; eye, nose, and throat irritation; fatigue; and dizziness) sometimes without an identifiable etiology.
2. c. A panel of the World Health Organization (WHO) recommended that the terms MCS and EI be replaced by idiopathic environmental intolerance (IEI), arguing that use of the word sensitivity may be construed as connoting an allergic cause and that the link between symptoms and exposure is unproven.
3. a. The Quick Environmental Exposure and Sensitivity Inventory (QEESI) can be used to assess chemical intolerance.
Chapter 50
1. d. Risk can apply to almost any activity or event, such as the likelihood for injury when playing a sport or driving a car, the chance for developing a disease from exposure to pathogens or chemicals, or the possibility for property damage from a natural catastrophe.
2. d. Risk assessment is a means or methodology to quantify risk, but it is important to recognize that it is a process and not a science.
3. a. The exposure assessment step in a risk assessment is used to estimate the magnitude and probability of uptake from the environment by any combination of oral, inhalation, and dermal routes of exposure.
4. a. The key element to the precautionary principle is that action should be taken in the face of uncertainty rather than delaying action until more “evidence” is generated.
5. d. Risk managers use a value-laden approach to consider risk, along with other factors, in determining what level of risk is acceptable and in developing measures that would prevent, reduce, or maintain risk at those levels.
6. b. RELs are derived by identifying and dividing the NOAEL (or BMD) by uncertainty factors to account for inadequacies in the database, incomplete scientific knowledge, and protection of more sensitive individuals.