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42 Cards in this Set
- Front
- Back
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Which etiological agent was
responsible for most cases of illness due to waterborne-disease outbreaks in the United States in the 1990s? |
Cryptosporidium
parvum was responsible for illness in 403,271 persons, the greatest number of cases of illness due to outbreaks of waterborne disease in the United States in the 1990s. |
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The most important risk factor
for heat-related illness is |
Older adults over the age
of 65 are particularly at risk of death due to heat-related illness because of decreased response of the cardiovascular system during hot weather. Very young children under the age of 1 are also at risk, but less than older persons. Heat-related illness is seen more frequently in lower-socioeconomic areas, presumably because of no access to air conditioning and good ventilation and because of higher temperatures in urban areas (heat islands). Obesity and prior history of heat stroke also increase the risk, but to a much lesser degree than older age. Drugs that inhibit sweat production, cause dehydration, and reduce cutaneous blood flow (atropine, antidepressants, diuretics, etc.) also increase susceptibility to heat |
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Following an accident in a
nuclear laboratory, some workers were exposed to 300 rem (3 Sievert) of radiation. They are immediately sent to your emergency department. Which of the following effects will most likely occur among the majority of these workers? |
Disturbances begin to
occur at exposures above 100 rem. Following an acute exposure to 100 to 200 rem of ionizing radiation, mild hematopoietic disturbances may occur (5% at 100 rem and 50% at 200 rem) after a few weeks, which only warrant surveillance. Some patients may have vomiting three hours after the exposure. Between 200 and 600 rem, more severe hematopoietic disturbances will occur, with a peak at 4 to 6 weeks, requiring transfusions, antibiotics, and hematopoietic growth factors. Patients will vomit within two hours. Extreme disturbances will occur after an acute exposure of 600 to 1000 rem, with a high case fatality rate (80 to 100% within two months) . Vomiting will occur within one hour. All patients with exposures above 1000 rem will die, with early onset (1 to 14 days depending on exposure) of gastrointestinal syndrome (diarrhea, fever, and electrolyte disturbances) and central nervous system problems dominating the clinical picture. |
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Haddon matrix is used
for assessing interventions for the prevention of |
This is a systematic
approach to injury prevention developed by William Haddon Jr. of the New York State Department. The matrix categorizes interventions as modifying the host, agent, and environment either before, at the time of, or after the event |
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1 what is neurosensorial loss.
2 Conductive losses 3Noise-induced hearing loss is typically most pronounced at 4 Hearing loss due to noise is 5 (presbycusis), 6 Middle-ear or external-ear dysfunction 7 Nonorganic hearing loss (that is faking hearing loss) |
1 When both air and bone conduction are decreased, there is a neurosensorial loss.
2 Conductive losses are characterized by a gap between air and bone conduction where the air-conduction loss exceeds the bone loss. 3 Noise-induced hearing loss is typically most pronounced at 4000 Hz. As the deficit becomes more severe, hearing begins deteriorating at less that 4000 Hz (audiogram B). 4 Hearing loss due to noise is sensorineural: air conduction will be better than bone conduction with the Rinne test (tuning fork). 5 Aging can also cause a sensorineural hearing deficit (presbycusis), but the loss generally increases with the frequency: deficit at 8000 Hz will be more pronounced than at 4000 Hz, and the audiogram shows a slow descending curve 6 Middle-ear or external-ear dysfunction will cause a discrepency between bone and air conduction, as illustrated in . 7 Nonorganic hearing loss (that is faking hearing loss) can usually be discover ed by: persons will tend to claim gradual hearing difficulties with poor correlation with speech discrimination. There will also often be test-retest variability |
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Trichinell
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Infection of hogs with nematodes
of the genus Trichinella can be prevented by ensuring that all garbage and offal fed to the hogs are heat-treated to destroy the cysts or, preferably, by using feed devoid of animal meat, such as grain. Prohibition of marketing of garbage-fed hogs is easier to enforce than inspection to ensure that all garbage is properly cooked. The disease is transmitted by ingestion of larvae in hog skeletal muscle, not by hog feces. Thorough cooking of pork and pork products so that all the meat reaches at least 71°C (160°F) destroys the encysted larvae. Freezing pork also destroys the larvae if adequate time-temperature schedules are followed. In order to be effective, freezing must be done at −15°C (−5°F) for 30 days if the piece of meat is 15 cm in thickness or less. |
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simplest effective method to prevent Cryptosporidium
parvum infections Which engineered water purification system is the most effective for the elimination of Cryptosporidium parvum? |
simplest effective method to prevent Cryptosporidium
parvum infections if drinking water is contaminated or has not been treated adequately. The water intended for drinking should be boiled for 1 min. Immunosuppressed persons, such as those with HIV, are particularly at risk of severe infections Slow sand, rapid granular, or membrane filtration is the most effective water treatment method to remove Cryptosporidium cysts, as they are not destroyed by disinfection |
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The major environmental
source of lead absorbed in the human blood stream in adults is |
Although most lead
intake in humans is from ingestion of lead-contaminated food (about 0.1 mg of lead is ingested daily per person), the amount of lead that is absorbed after inhalation of lead-contaminated air is of greater significance because up to 50% of inhaled lead, compared with only as much as 10% of ingested lead, is absorbed and circulated through the blood |
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The most appropriate
intervention for level of sound is |
Exposures of 85 dB or
more for 8 hours a day or more require the implementation of a hearing conservation program This program includes noise monitoring, engineering controls, administrative control, worker education, selection and use of hearing protection devices (HPD), and periodic audiometric evaluations. Engineering controls where possible are always the preferred method of controlling sound levels Administrative controls include reducing the amount of time the worker is exposed to high levels of sound Hearing devices must be able to bring the level of sound to 90 dB or less, the permissable exposure level for sound. However, workers may not always wear these devices. At levels of sound below 90 dB, OSHA requires that HPD be made available to workers. At level 90 or above, HPD must be provided and proper use must be enforced by the employer |
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A 42-year-old welder is brought
in the emergency room complaining of a sore throat, headache, and myalgias. He also started feeling a tightness in the chest and shortness of breath. He works in an electroplating operation brazing and cutting metals. Pulmonary function tests reveal a reduced forced expiratory volume. The chest x-ray is normal. copper poison lead chromium |
Acute exposure to mercury results in cough, inflammation of the
oral cavity, and gastrointestinal symptoms. Renal injury is of particular concern. Neurological symptoms can later occur. Mercury is often used in the manufacturing of control instruments (such as thermometers). Dimercaprol Copper toxicity (in the United States) is primarily due to accidental ingestion or suicide attempts and leads to intravascular hemolysis and methemoglobinemia. No specific treatment exists. The initial symptoms associated with acute exposure (ingestion or inhalation) of lead are primarily gastrointestinal (abdominal cramps). Encephalopathy can follow. Lead is used intensively in the production of storage batteries. Chromium is used in plating. Acute exposure results in irritation of eyes, nose, and throat with epistaxis. Chromium is a known carcinogen (lung cancer). Dermatologic conditions are common among chromium workers (ulcerations with delayed healing on fingers, knuckles, and forearms) and are treated with 10% CaNa2 EDTA ointment is used for treatment. |
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Toxicology is the study of adverse
effects of chemicals on living organisms. Which of the following occurrences would be indicative of the most important nonthreshold effect in humans |
Adenocarcinoma
Substances causing adverse biological effects in humans can be classified as reproductive, renal, and respiratory toxins; neurotoxins, dermatotoxins, and hepatotoxins. It is assumed that there may be some form of dose-response relationship and that there is a minimal exposure below which a toxic effect will not occur (the threshold). The absence of threshold is assumed for any substance that is carcinogenic, mutagenic, and/or teratogenic. |
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What proportion of cancers
in humans is estimated to be the result of environmental factors? |
90
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heat exposure
1Heat stroke 2 heat cramps 3 heat syncope 4 heat exhaustion what is heat index |
1 Heat stroke is characterized by the presence of mental status changes
and a core body temperature of more than 39° Celsius. Cardiovascular collapse will occur if not treated immediately as the body temperature may reach up to 41.1° Celsius. This is a medical emergency requiring IV hydration and rapid cooling: cool water or isopropyl alcohol 70% on the body with fanning, sponge baths, ice packs on the groin/axilla/neck, and/or iced gastric lavage until the core body temperature drops to 39° Celsius. Patients should be advised to avoid heat exposure for at least 4 weeks because hypersensitivity to heat may persist for a long period of time after an episode of heat stroke. 2 Heat cramps are characterized by painful muscle cramps along with some nausea and vomiting. The core body temperature is normal. This is caused by sodium depletion due to sweating: the patient should be placed in a cool environment and hydrated with a balanced salt solution. Rest for at least 1 to 3 days is recommended. 3Heat syncope is a sudden loss of consciousness due to vasodilation secondary to heat. 4Heat exhaustion is what this patient is experiencing. She should be placed in a cool and shaded environment. This patient should also receive hydration and salt replenishment with IV fluids. Milder cases can be treated with oral hydration. At least 1 day of rest is recommended after heat exhaustion. Heat index guidelines are developed by the National Weather Service and predict risk of heat-related disorders based on ambient heat and humidity. |
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Which of the following tests
is the most frequently used rapid screening test to assess mutagenicity/ carcinogenicity of a chemical substance? |
All the tests listed can
be used to screen substances for mutagenesis and carcinogenesis, that is, their ability to interact with genetic material and DNA. The Ames test is the most commonly used rapid screening test and is a bacterial mutation assay. It tests for the reversion of a histidine-requiring Salmonella typhimurium mutant to the wild type. It is very sensitive to DNA damage. The other tests are more sophisticated, take more time, and are more expensive |
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Commercial airline pilots have
higher exposures to which type of radiation compared to the general population? |
cosmic radiation,
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Radioactive waste is best disposed
by |
Landfills are used to dispose
of nonliquid waste only. This is the only method of disposing of radioactive waste safely. |
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On a hot summer day in a
large urban center located in the southwestern United States, an emergency room department reports an increase in admissions for asthma in children and young adults, but not among patients suffering from chronic bronchitis or ischemic heart disease. The most likely air pollutant responsible for the exacerbation of asthma is |
The major air pollutants
are particulates, sulfur oxides, carbon monoxide, oxides of nitrogen, hydrocarbons, lead, and ozone. The latter is formed by sunlight irradiating an atmosphere containing hydrocarbons and oxides of nitrogen, and has been associated with Southern California smog. It has primarily been linked to an exacerbation of asthma. |
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Which of the following physical
characteristics of water is the most important impediment to disinfection? |
Turbidity is a major impediment
to disinfection |
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Which of the following residential
environmental pollutants is the leading cause of lung cancer |
Tobacco is still
a leading cause of lung cancer. Radon has also been associated with lung cancer, and the combination of radon and tobacco smoke can be synergistic. |
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A 28-year-old woman presents
with nausea, vomiting, and diarrhea. She has no fever. Her history reveals that she attended a reception about six hours ago. She ate roast beef with gravy, salad, and had cream-filled pastries for dessert. Prevention of this food-borne illness could have been achieved by |
The short incubation
period and symptoms are characteristic of food poisoning due to the toxin produced by Staphylococcus aureus. Organisms and toxin are not destroyed by freezing. Although the organisms can be killed by heating food to 66° Celsius (150° Fahrenheit), the preformed toxin generally survives. Optimum growth of the bacteria occurs at 59° to 99° Fahrenheit (growth is inhibited at below 39° Fahrenheit), with toxin production optimal after 4 to 6 hours. The source is human skin, mouth, and nose. Proper hand wash ing by food handlers and excluding those with skin infections is the best way to prevent contaminatio |
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Dye workers are susceptible to...
Liver cancer has been associated with exposure to.... .hematologic cancers are associated with exposure... |
Dye workers are susceptible to
bladder cancer due to exposure to β-Naphtylamine and benzidine. The most common presenting symptom will be gross hematuria or microscopic hematuria Liver cancer has been associated with exposure to vinyl chloride while hematologic cancers are associated with radiation and benzene exposure |
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A 30-year-old patient presents at an evening walk-in clinic after work
complaining of chills, fever, and malaise of acute onset. He started coughing and feeling out of breath late in the afternoon. Inspiratory crackles are present on chest auscultation. The chest x-ray is normal. The complete blood count reveals 12,000 WBC with 70% PMNs. His past medical history is benign. No one else in the household is sick. He says some of his coworkers have a cold. He works in a pet shop in the bird section. He is not taking any medication. He states he had a similar episode a few weeks ago that resolved after a few days of rest at home. The most appropriate management is to prescribe wha is the treatment for severe or progressive hypersensitivity pneumonitis psittacosis - as d/d |
These
symptoms are typical of hypersensitivity pneumonitis, which can often be confused with infectious causes such as influenza or Mycoplasma pneumoniae. Chest x-ray may be completely normal even in symptomatic individuals. However, typically, the chest x-ray may show bilateral reticulonodular infiltrates. The acute form is characterized by the appearance of symptoms a few hours after short-term high exposure, and resolves after a few hours or days. Treatment should primarily consist of avoiding the causative agent or wearing respiratory protective equipment. Acute episodes resolve on their own without glucocorticosteroids Prednisone is the treatment for severe or progressive hypersensitivity pneumonitis Psittacosis has an incubation period of 7 to 14 days, can be associated with splenomegaly (10 to 70% of cases), and the x-ray generally shows diffuse patchy infiltrates |
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Which of the following factors
of air travel is most likely to adversely impact a patient with cardiopulmonary disease |
Lower barometric
pressure associated with air travel will lower the tension of oxygen in the inspired air, the alveolar oxygen tension, and arterial oxygen saturation, which could lead to an exacerbation of coronary artery disease deficiency Immobilization for long periods of time can increase the risk of thromboembolic disease, which may be more of an issue for pregnant women. Getting up periodically to walk up and down the aisles may help alleviate this problem |
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Which of the following smokers
has the highest risk of developing lung cancer? a. An asbestos worker b. A uranium miner c. A coal worker d. A textile worker e. A sandblaster |
The effect of asbestos
and smoking are synergistic for the development of lung cancer Uranium workers, due to exposure to radon, will also be at greater risk, particularly if they are exposed to higher levels of radiation |
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maximum altitude of 8,500 feet Acute mountain sickness
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Headache, nausea, and sleep disturbances
Acute mountain sickness, is the most common altitude illness and usually occurs in altitudes above 8000 feet (2500 m). Symptoms occur about 3 to 12 hours after reaching that level. It will resolve spontaneously after 5 to 7 days at altitude. Acetazolamide 125 to 250 mg every 8 to 12 hours starting 24 hours before the ascent and to be continued for 2 days at altitude or 500 mg SR tablet every 24 hours and continued for 2 days at altitude may alleviate symptoms. Dexamethasone 4 mg every 6 to 12 hours is reserved for those ntolerant/allergic to Acetazolamide or for treatment of more serious altitude sickness. |
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High-altitude pulmonary edema
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High-altitude pulmonary edema can occur
(1 to 2% of individuals) at altitudes of over 10,000 feet. Symptoms of tachypnea and dyspnea with rales start 2 to 4 days before reaching that altitude. They can be rapidly fatal if not treated. Treatment consists of rapid descent and nifedipine |
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High-altitude cerebral edema
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Headache, ataxia, and altered mental
status High-altitude cerebral edema occurs occasionally (less than 1% of persons) at altitudes above 15,000 feet, but may occur as low as 9,000 feet in susceptible individuals. |
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Persons who were rescued from the
water are more likely to experience hypothermia than those exposed only to cold air. The most likely mechanism is |
Conduction is the principal
source of heat loss during cold-water immersion. Thermal conductivity of water is 25 times that of air. Alcohol can precipitate heat loss in both air or water immersion due to the vasodilation it produces. Exhaustion may also be a contributing factor to heat loss in water versus air |
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During a diving expedition to
explore sunken ships, one of the divers starts to experience lightheadedness, dizziness, ataxia, and nausea after reaching 110 feet in depth.what is the most likely diagnosis? |
Nitrogen narcosis is due
to increased partial pressure of nitrogen in the nervous system and symptoms are analogous to alcohol intoxication. |
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Barotrauma
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Barotrauma (barosinusitis, middle
ear or barotitis media) is due to the mechanical effects of expansion and contraction of gases when pressure differences exist between the body cavities and the environment. These two syndromes are manifestations of compression sickness occurring during descent |
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The bends
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The bends (so called because
the person can be stooped because of severe joint pain) are a form of decompression sickness (also called caisson disease) due to inadequate elimination of dissolved gas after a dive, affecting the skin and joints Decompression sickness can occur either after a too rapid ascent from a dive below 9 meters or a sudden pressure loss at altitudes above 7000 feet. |
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is causally associated with
pneumoconiosis? |
Pneumoconiosis, a
fibrosing disease of the lungs, usually occurs as a result of occupational exposure to air that contains particulate matter, especially mineral dust. Anthracosis, silicosis, asbestosis, and berylliosis are among the more than 30 forms of pneumoconioses that have been described in the literature. Sulfur oxides, nitrogen oxides, oil fumes, and cigarette smoke are likely to cause acute bronchospasm or to exacerbate preexisting diseases such as chronic bronchitis and emphysema. |
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A couple presents to the infertility
clinic because of inability to conceive for over one year. A semen analysis on the male reveals oligospermia. He works for a company that manufactures storage batteries. A blood level should be obtained for which of the following agents |
Carbon disulfide, chloroprene,
estrogens, excessive heat, lead, and ionizing radiation have all been strongly linked to oligospermia. Exposure to lead can occur during the manufacturing of storage batteries. Chromium, nickel, and antimony levels are measured in urine, but are not associated with oligospermia |
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A large explosion occurs at a
construction site during excavation. None of the workers appear injured. Some of them were exposed to sound pressure levels of 190 dB. Which of the following is the most likely outcome for these workers? |
Acute exposures to
sound pressure levels above 180 dB will result in a traumatic rupture of the tympanic membrane and conductive hearing loss. The rupture should repair spontaneously unless infection occurs. If the loss persists for more than three months, surgical repair is possible. Sensorineural loss is generally due to fractures or trauma to the inner ear. Mixed hearing loss can occur secondary to fractures of the temporal bone, when both the middle and the inner ear are traumatized |
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A 50-year-old presents with
dyspnea on exertion, without cough or chest pain. He has no history of asthma, chronic bronchitis, or heart disease. He does not smoke. He is employed in the aircraft industry and his work consists of producing metal alloys. His chest x-ray reveals small, rounded, and irregular opacities. Pulmonary function tests show decreased diffusion. The Kveim for sarcoidosis is negative. The most likely etiologic agent responsible for these findings is |
Beryllium
causes a syndrome similar to sarcoidosis. Only individuals who are sensitized to the metal will develop the disease. It can also cause granulomas of the skin. |
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worker presents with hyperkeratosis,
hyperpigmentation, and anemi |
Arsenic
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A worker presents with Fanconis
syndrome |
Cadmium
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worker experiences fever,
chills, profuse sweating, cough, and chest pain that resolves after 48 hou |
Zinc
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worker presents with ataxia,
loss of visual fields, and auditory disturbances |
Mercury
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arsenic Beryllium cadmium nickel chromium Lead manganese mercury zinc.
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Chronic exposure to arsenic causes the symptoms worker presents with hyperkeratosis,
hyperpigmentation, and anemia . Acute exposure can lead to cardiovascular collapse. Beryllium can cause upper respiratory symptoms after acute exposure, and granulomas with a chronic debilitating disease (respiratory symptoms accompanied by weight loss and fatigue) after chronic exposure (berylliosis). Chronic exposure to cadmium can cause Fanconis syndrome (only metal to cause this). Chronic exposure to chromium can lead to nasal perforation and lung cancer. Acute exposure to nickel may result in bronchospasm inhalation) and dermatitis (skin contact). Lead exposure leads to neurological disturbances such as encephalopathy (if acute), neuropathy, and neurobehavioral changes. Chronic exposure to manganese may lead to a Parkinsonlike disease. Exposure to mercury can cause ataxia, spasticity, parethesias, and visual disturbances. The symptoms //... worker experiences fever, chills, profuse sweating, cough, and chest pain that resolves after 48 hours,,,,,,, are often called metal fume fever and are typical of an acute exposure to zinc. |
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Match the following clinical
presentation with the most likely solvant exposure. a. Hydrocarbons b. Petroleum distillates c. Alcohols d. Glycols e. Ketones f. Esters g. Phenols |
all the solvents listed will cause some form of CNS depression after acute exposure (drunkenness, slurred speech, dizziness, headache).
Exposure occurs by inhalation or skin absorption. They will also all cause some form of dermatitis after chronic skin exposure (cracked and erythematous skin). Chronic exposure to esters and ketones results only in dermatitis, with no other health effects demonstrated. Chronic exposure to all types of hydrocarbons and petroleum distillates results in neurobehavioral dysfunction and short-term memory loss, difficulty concentrating, fatigue. Methyl alcohol is widely used as an industrial solvent and one-third methyl alcohol is used in formaldehyde. Chronic toxicity (which can occur through inhalation) produces optic neuropathy (particular to this type of alcohol; not seen with other solvents). Only acute exposure to phenols causes the tissue destruction hepatic and kidney necrosis . Although all solvents can potentially cause some form of hepatotoxicity if exposure is high and long enough, halogen and nitro group are particularly toxic to the liver. Chronic exposure to glycol has been associated with encephalopathy and reproductive toxicity in laboratory animals. |
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Match the following organ toxicity
with the most likely exposure. a. Arsenic b. Carbon tetrachloride c. Quartz d. Coal e. Cotton f. Acrylic |
Quartz is associated with silicosis, coal with the coal workers pneumoconiosis, and cotton with byssinosis.
Acrylic exposure may cause contact dermatitis and some respiratory and mucous membrane irritation. |
