REHS Exam Questions and Answers, Latest Updated 2024/2025 (Graded A+)

A factor or agent which increases the risk of cancer is known as a a. teratogen b. mutagen c. carcinogen d. fomite - carcinogen 2. The four major causes of death among all age groups of Americans include all of the following except. a. homicide b. accidents c. malignant neoplasms d. heart disease - homicide 3. In recent years, the largest number of rabies cases were associated with a. skunks b. bats c. dogs d. raccons. - skunks 4. Asbestosis is caused by fine silicate fibers retained in the a. kidneys b. lungs c. colon d. abdomen - lungs 5. An illness due to a specific infectious agent or its toxic product which is transmitted from a reservoir to a susceptible host either directly or indirectly is called a. an infectious disease b. a communicable disease c. a genetic disease d. a noncommunicable disease - a communicable disease 6. Rocky mountain spotted fever is spread by a. flies b. spiders c. cockroaches d. ticks - ticks 7. Mycotoxins are poisonous chemicals produced by REHS Exam Questions and Answers Latest Updated 2024/2025 (Graded A+) a. bacteria b. vertebrates c. viruses d. fungi - fungi 8. The study of the occurrence, frequency, and distribution of disease is a. entomology b. biology c. endocrinology d. epidemiology - epidemiology 9. Which of the following organisms are most resistant to unfavorable environmental conditions and indicate past or possibly intermittent pollution? a. fecal streptococci b. escherichia coli c. aerobacter aerogenes d. clostridium sporulates - clostridium sporulates 10. Engineering controls are a. controls that isolate or remove hazards from the work place b. less effective than good training c. the last option that should be considered d. less effective than personal protection processes - controls that isolate or remove hazards from the workplace 11. Which of the following is not considered a satisfactory solution to the problem of chemical contamination in Well systems? a. abandoning the well b. boiling the water c. building a new, properly constructed, drilled well - boiling the water 12. Which of the following chemicals is most widely used to destroy microorganisms? a. chlorine b. copper sulfate c. chloramine d. hydrogen sulfate - chlorine 13. Which of the following is not a practical method for removal of cadmium? a. ion exchange b. lime softening c. reverse osmosis d. iron coagulation - reverse osmosis 14. Which of the following is not a commonly accepted method of device to prevent backsiphonage? a. vacuum breakers b. cross-connections c. air gap separation d. back pressure units - cross-connections 15. This substance is the first product of the decomposition of organic matter. Its presence in water usually Indicates "fresh pollution" of sanitary significance. What is it? a. ammonia b. sugar c. carbon dioxide d. hydrogen sulfide - ammonia 16. One of the most common reasons for the contamination of wells drilled through rock, clay, or hardpan is a. seepage of pollutants through soil b. failure to seal well casings properly c. porosity of the rock d. use of inferior quality well casings - failure to seal well casings properly 17. In emergencies, small quantities of water can be disinfected by boiling or using a. aluminum salts b. tincture of iodine c. salt tablets d. direct exposure to sunlight for 22 hours - tincture of iodine 18. Back flow of nonpotable materials into the potable water system may occur by a. back pressure b. backsiphonage c. vacuum in the volume d. a and b above - a and b above 19. Which of the following statements should not be a consideration in locating a groundwater supply? a. the probable travel of pollution through the ground b. the well construction practices and standards c. the sanitary seal provided at the point where the pump lines pass out of the casing d. the distance that the water will need to travel - the distance that the water will need to travel 20. It is known that some common pathogenic organisms found in wastewater will survive more than ____ of harsh temperature extremes a. 2 months b. 5 months c. 2 years d. 5 years - 2 years 21. A storm sewer is used to a. remove rain or other standing surface water b. remove sewage and storm water c. remove household water waste and gutter drain water d. remove non-toxic, non-hazardous wastewater - remove rain or other standing surface water 22. Stream pollution is sometimes apparent by a. increased levels of available oxygen in the water b. a zone of degradation c. large numbers of crayfish and cristivomer species d. large numbers of small fish - a zone of degradation 23. If the septic tank will also have a garbage disposal unit feeding into it a. the size of the tank would be increased by 50 percent b. the tank should have an agiator c. the tank should not be equipped with a gas baffle d. the tank should not be constructed with precast concrete - the size of the tank would be increased by 50 percent 24. How often should a septic tank for a private home be serviced? a. every year b. every 5 to 10 years c. every 3 to 5 years d. every 10 years - every 3 to 5 years 25. Plants absorb certain constituents of wastewater, using wastewater for irrigation of consumable plant products may present a health hazard to humans if the water contains a. nitrates b. iron c. cadmium d. chlorides - cadmium 26. A measure of the relativity constant rate at which clear water, maintained at a relatively constant depth, will seep out of a standard size test hole that has been previously saturated is the a. hydraulic conductivity b. soil permeability test c. soil percolation test d. Baird-Parker saturation test - soil percolation test 27. The ability of a soil to absorb and allow water and air to pass through is related to all of the following except a. chemical composition b. texture c. cation exchange capacity d. granular structure - cation exchange capacity 28. Bacteria that require oxygen for their growth are called a. anaerobic bacteria b. aerobic bacteria c. viruses d. fungi - aerobic bacteria 29. The examination of the stool for cysts and/or ova is the common diagnosis for which food borne pathogen? A. Parasitic infections B. Viral infections C. Bacterial infections D. Non-infectious agents E. None of the above - parasitic infections 30. If you are counseling a pregnant patient, what foods should she avoid to decrease her risk for listeriosis? A. Honey B. Fresh soft cheese C. Sauerkraut D. Cooked mushrooms E. Caffeine - fresh soft cheese 31. Which scenario(s) may present a risk to immunocompromized patients. A. Animals in the Home Use B. Coming in contact with individuals after they have been given a live virus vaccine. C. Eating raw oysters D. Drinking non-pasteurized juices or unchlorinated water E. All of the above - all of the above 32. What food borne illness may present with chocolate-brown colored blood? A. Nitrite poisoning B. Organophosphate poisoning C. Botulism D. Mercury poisoning E. Tin poisoning - nitrite poisoning 33. Approximately how many people die per year in the U.S. of food-borne illness? A. 5,000 B. 100 C. 9,000 D. 100,000 E. 50 - 5,000 34. In the U.S. the pioneering Pure Food and Drug Act was passed in 1906 stimulated by journalistic exposures of inferior conditions in the food industry and by Upton Sinclair's 1906 novel titled? A. Silent Spring B. The Coming Plague C. To Kill a Mockingbird D. The Jungle E. The Catcher in the Rye - The Jungle 35. Which bacteria in large numbers can survive extended storage in cheddar cheese? a) Salmonella b) Brucella sp. c) Shigella d) Clostridium perfringens - Salmonella 36. Which of the following is non-toxic to aquatic organisms, a good viricide, and adds oxygen to treated wastewater effluents? a. ozone b. calcium hypochlorine c. sulfur dioxide d. chlorine dioxide - ozone 37. The typical limitation of use of the septic tank absorption field system is due to a. cost b. land use considerations c. soil type and size requirements d. appearance - soil type and size requirements 38. Which of the following is true about disposal of animal wastes? a. If wet manure is plowed under, fly eggs present will not hatch. b. Composting of manure takes advantage of the inclination that larvae move out and away from moist manure in search of a dry place to pupate. c. Where a small number of animals are kept, the manure should be collected once a week. d. Odors associated with the handling and disposal of these wastes do not determine the disposal method or its location. - composting of manure takes advantage of the inclination that larvae move out and away from moist manure in search of a dry place to pupate 39. Resource recovery and reduction of solid wastes should start a. at the point of generation b. at the sanitary landfill c. in the home d. at the transfer station - at the point of generation 40. ______can be recovered from refuse by burning it in a refractory lined incineration or water-wall incinerator. a. glass b. aluminum c. ferrous metal d. energy - energy 41. Incinerators are rated in terms of a. percent fuel capacity per day b. BTU's per day c. tons of burnable waste per day d. cubic feet of solid waste per day. - tons of burnable waste per day 42. The three essentials for combustion in an incinerator are a. temperature, time and heat b. time, temperature and moisture c. temperature, heat and fuel d. time, temperature and turbulence - time, temperature and turbulence 43. The second step of the combustion process in an incinerator requires a high temperature of at least a. 1500o to 1600oF b. 1500o to 1800o F c. 1900o to 2000o F d. 1800o to 1900o F - 1500 to 1800 F 44. A landfill site should not a. be located near a major highway b. be given and attractive entrance and approach road c. house equipment on site d. be inexcessible during bad weather conditions - be inexcessible during bad weather conditions 45. Determining what a landfill can be used for when completed should be planned a. when the landfill is half full b. before you build the landfill c. when the landfill is full d. any time during the operation of the landfill - before you build the landfill 46. Hazardous waste is governed by the a. Clean Air Act b. Occupational Safety and Health Act c. Resource and Conservation and Recovery Act d. Food and Drug Act - Resource and Conservation and Recovery Act 47. Which of the following is not a characteristic of hazardous waste? a. ignitability b. corrosivity c. reactivity d. combustibility - combustibility 48. The EPA requires that dioxin-bearing wastes be ________ destroyed or reduced before disposal in a secure hazardous waste landfill. a. 99.99 percent b. 95.00 percent c. 99.9999 percent d. 0.05 percent - 99.9999 percent 49. When two pollutants are combined, the effects are greater than the sum of the individual effects. This is called? a. commensalism b. synergism c. magnification d. multiplication - synergism 50. Air is vital to existence. In fact, humans breathe in a day's time an average of a. 3 to 4 pounds of air b. 35 pounds of air c. 37 pounds of air d. 1600 ft of air - 1600 ft of air 51. Ozone reduces the useful life of all of the following except a. rubber b. textiles c. dyes d. nylon - nylon 52. Major effects on humans are caused by Los Angeles and London type smog, along with what two pollutants? a. sulfur dioxide and hydrogen fluoride b. sulfur dioxide and carbon monoxide c. hydrogen sulfide and peroxacyl nitrates d. ozone and nitrogen dioxide - sulfur dioxide and hydrogen fluoride 53. Photochemical smog has been reported in congested areas with a. large industries b. chemical processing plants c. industries processing hazardous wastes d. high motor vehicle traffic - high motor vehicle traffic 54. _________have been known to cause crippling skeletal damage to cattle through ingested contaminated vegetation. a. sulfides b. fluorides c. nitrates d. chlorides - fluorides 55. What size particle can reach the lowest parts of the lung? a. 10 microns b. 25 microns c. 2.5 microns d. any size particle - 2.5 microns 56. Street dust would be considered what type of pollution? a. paradox pollutant b. fugitive pollutant c. uncontrolled pollutant d. laps rate - fugitive pollutant 57. A primary pollutant is a. one that is formed in the atmosphere as a result of reactions such as hydrolysis, oxidation, and photochemistry b. one that is found in the atmosphere due to natural reactions c. one that is found in the atmosphere in the same form as it exists - one that is found in the atmosphere due to natural reactions 58. How are total suspended particles measured? a. flame photometry and weighing b. gas filtration c. flame ionization d. collection and weighing - collection and weighing EMAIL ME: For help with report, Assignment, Essay and thesis writing 59. Which of the following inversions develop at night under conditions of relatively clear skies and very light winds? a. subsidence inversion b. frontal inversion c. radiational inversion d. stack emission inversion - radiational inversion 60. The pitch of a sound is determined primarily by a. frequency b. wavelengths c. sound pressure d. all of the above - frequency 61. The distance that a sound wave travels in on cycle of period is the a. sound intensity b. wavelength of the sound c. sound pressure d. frequency - wavelength of the sound 62. The speed with which sound travels through a particular medium is dependent on a. the compressibility of the medium b. the density of the medium c. the compressibility and density of the medium d. none of the above - the density of the medium 63. A __________is a dimensionless unit to express physical intensity or sound pressure levels. a. noise level b. decibel c. hertz d. sound pressure level (SPL) - decibel 64. If 10 decibels is 10 times more intense than one decibel, how many times more intense in 20 decibels than one decibel? a. 20 b. 30 c. 100 d. 1000 - 100 65. The first Federal standards for occupational exposure to noise were issued by a. the Department of Transportation b. the Federal Aviation Administration c. the Department of Housing and Urban Development d. the Department of Labor - the Department of Labor 66. The shorter the wave length a. the higher the frequency and lower the energy b. the lower the frequency and energy c. the lower the frequency and higher the energy d. the higher the frequency and energy - the higher the frequency and energy 67. The roentgen is a measure of the ionization in air produced by exposure to a. x-rays or gamma rays b. alpha particles c. beta particles d. all of the above - x-rays or gamma rays 68. The term "rad" means a. required administered dose b. radiation admitted dose c. roentgen absorbed dose d. radiation absorbed dose - radiation absorbed dose 69. The term "half-value layer" (HVL) is used to designate the thickness of a particular material that will reduce by ½ the intensity of radiation passing through the material. Beta radiation is commonly eliminated by a. lead b. concrete c. glass of plastic d. aluminum - glass of plastic