Final REHS Exam Prep II

Which of the following factors would least contribute to the emergence of a new infectious disease?

Heat disinfection

Listeriosis is commonly associated with…?

Contaminated food

The basic principles of diseases of disease control include all of the following except…?

Lag phase

The interval between exposure to an infectious agent and the appearance of the first symptom is called the…?

Incubation period

Which soil conditions are most favorable for the removal of viruses?

Fine loamy sand over coarse sand and gravel

Which of the following organisms are most resistant to unfavorable environmental conditions and indicate past or intermittent pollution?

Clostridium sporulates

Which of the following is not considered a satisfactory solution to the problem of chemical contamination in well systems?

Boiling the water

Which of the following chemicals is the most widely used to destroy microorganisms?

Chlorine

The control of corrosion in piping requires all of the following steps except…?

An increase in water velocity

Which of the following is the best method of backflow control?

Air gap separation

Control of infectious, intestinal disease of humans requires…

• provisions of safe water supplies

• Proper waste disposal

• Personal hygiene

What does it mean when a body of water has a high JTU?

It has high turbidity

The presence of which of the following is the most easily identified by lab analysis in water contaminated by feces?

Coliform

NTU’s are most commonly used to…?

Determine turbidity

A safe distance between a well and a waste disposal system is dependent on…?

• chemical processes

• Physical processes

• Biological processes

The geophysical methods used to identify and investigate the extent and characteristics of ground water pollution include….?

Geomagnetics

Electromagnétics

Electrical resistivity

What is the first step in evaluating the safety of a potential water system?

A detailed sanitary survey of the water supply

What are the examples of groundwater systems?

Dug, bored, driven, and drilled wells, rock and sand or earth springs, and inflammation galleries

What causes water hardness?

Dissolved calcium and magnesium biocarbonates, sulfates, chlorides in groundwater

The quality of surface water depends on…?

The watershed area drained, land use, location and sources of pollution, and the natural agencies of purification.

Which of the following is not commonly used for the disinfection of waters?

Silver nitrate

Hydropneumatics or pressure-tank water systems are suitable for…?

Small communities, housing developments, private homes and estates, camps, food service operations, and hotels

The hydropneumatic tank typically contains ___ of its volume as water…?

20%

Water containing nitrates generally indicates…?

Evidence of previous pollution

In a stratified reservoir, what zone is the best quality water in?

Metaliminion

Hydrogen sulfide can be fatal at exposure of…?

300ppm

Practical method of removing nitrates from water?

Ion exchange

Which of the following is not a practical method for removal of cadmium?

Reverse osmosis

The formula Q=AIR is used to determine …?

Rate runoff in a watershed

Of the following, which is not a variable to be considered when deciding upon a safe distance between a well and a sewage disposal system?

The number of individuals using the well.

Microbial pollution only travels a short distance through…?

Sandy loam or clay

Typically an abundant supply of groundwater may be yielded from…?

Sedimentary rocks

Which of the following is used to properly seal a drilled well to prevent contamination of the water supply?

Grouting

Which of the following WOULD NOT contribute to water hardness?

Sodium chloride

Which of the following disinfecting compounds can be used full strength for disinfection?

Sodium hypochlorite

All of the following will generally vary directly with the quantity of water used for domestic purposes except…?

Amount of minerals in the water.

Hardness of drinking water is desirable at levels of…?

50-80 mg/L

Alkalinity of water is desirable at levels of…?

30-100 mg/L

Domestic community water system pumps should be of such capacity as to deliver the average daily water demanded to the storage tank in…?

6 to 12 hours

Which would be the least effective method of controlling condensation of moisture inn food prep areas?

Increase air temperature

Clostridium botulinum spores are killed in…?

10-15 min at 80*C

Beef usually spoils first..?

On the surface

Which bacteria in large numbers can survive extended storage in cheddar cheese?

Salmonella

A solution of malachite mixed with ground meat will turn ____ if sodium sulfite has been added to preserve or mask the decomposition of meat.

Bright red

Adequate light is essential for proper operation, maintenance, and sanitation. A minimum of _____ is recommended on work surfaces.

5 foot candles

For custard filled pies to be considered safe, they should be heated to…?

190*F for ten minutes

Which food has the highest acceptable plate count of e.coli?

Cheese

Dry stored goods should be stored off the floor at least _____ to prevent their contamination.

6 inches

Contamination in a block of ice can be identified by _____ in the geometric center.

Discoloration

Practically all foods, weather canned, pickled, or dried…?

Deteriorate upon storage

In a food storage room, the artificial lighting should provide a minimum of…?

10 foot candles

Which minerals and chemicals cause problems in ice manufacturing ?

• calcium silica

• Iron and magnesium carbonates

• Aluminum oxide and manganese

Celery, a major source of salad contamination, has proven to be acceptable when…?

Immerse in boiling water for 30 seconds, then chilled under running tap water

Which of the following is the best to use when sanitizing food contact equipment?

• phenols

• Copper

• Zinc

NONE OF THE ABOVE

Dairy equipment can be disinfected with a chlorine solution of…?

200 mg/l

When disinfecting rubber valves and other parts of milking equipment with hot water, the water temperature should be _____ or a strong chlorine solution of _____ strength can be used instead.

180* to 190*F, 200 mg/l

In case of an emergency, raw milk may be rendered safe for drinking if _____ and then immediately cooled…?

Heated in a water bath temperature of 165*F

At what time and temperature specifications does a sweetened milk product have to be pasteurized?

150*F for 30 minutes

If the fat content of milk increases by 10% or more, the pasteurizer temperature must be increased by…?

5*F

Pasteurized milk quality is indicated by…?

• direct microscopic count, coliform test, standard plate count

• Phosphate test, taste and odor tests

The contamination of milk with sediments is typically the result of…?

Improper cleaning of the cow

Salty flavors in milk may be due to the use of milk from cows infected with…?

Hepatitis

Which of the following bacteria typically contains most of the pathogenic bacteria?

Mesophillic

Thermoduric bacteria grow best at a temperature range of…?

70 to 98*F

Shellfish spawning takes place between the months of…?

May and august

Dealers involved in interstate shipment and control of shellfish must have…?

A certification

Oysters grow best at what pH and temperature?

6.2 to 6.8 and 41F

Oysters free themselves of viruses and bacteria within ____ of exposure in seawater.

12 to 24 hours

Sandwich and salad mixtures should be placed in shallow pans at a depth not greater than ____ to accelerate the rapid cooling of the food

3 inches

The final rinse water temperature for a heat sanitizing machine dishwasher should be…?

180*F

What is the minimum period of wash time for a single tank conveyer dishwashing machine…?

15 seconds

A pool filtration system should filter the entire volume of water every…?

6 to 8 hours

The rate filtration should be ____ for a diatomite filter.

1 to 2 gpm/ft2

Eye irritation can be caused by prolonged exposure to water with a pH …?

Below 7.4

The acidity-alkalinity balance affects eye irritation, water coagulation and the…?

Effectiveness of chlorine

The addition of sodium biocarbonate is usually used to…?

Raise the alkalinity

To raise the pH, you add..?

Soda ash

A chemical commonly used to improve water clarity is…?

Alum

The best control of swimmers itch at a bathing beach is to….?

Add copper sulfate

The ideal pH range for swimming pools is…?

7.2 to 7.6

Rodents are the primary host for hantavirus. In particular, ____ appears to be the primary reservoir in the southeastern U.S.

Deer mouse

Bacteria may be carried in the digestive system of the housefly for as long as…?

4 weeks

A chigger is the larval stage of the…?

Mite

Pediculosis is an infestation of…?

Live

Storage of clothing, bedding, and any other lice infested items for at least _____ will cause the live to die of starvation…?

30 days

An infectious disease of the skin caused by burrowing of the female mite into the skin where it deposits its eggs?

Tularemia

The peak seasons for rats to breed in temperature danger zones…?

Spring and fall

The first step in a rat control program?

A community survey

Hazardous waste is governed by the…?

Resource Conservation and Recovery Act

Which component of clean dry air has the smallest volume?

Sulfur dioxide

What type of air pollution causes loss of chlorophyll in plants?

PAN

Glazing, silvering, or browning on the underside of a leaf is evidence that injury has occurred by…?

Peroxyacyl nitrates

Animal are primarily affected by the pollutants in the air…?

Through ingesting the vegetation

Injury to plants due to ____ shows up as flecks, stipple, and bleaching, tip burns, and growth suppression.

Ozone

______ can be formed as a result of the sun’s action on nitrogen oxides and hydrocarbons.

Ozone

The roentgen is a measure of the ionization in the air produced by exposure to…?

• x ray or gamma rays

• Alpha particles

• Beta particles

The term RAD refers to…

Radiation Adsorbed Dose

The term frequency cannot be described as…?

Particles

Which of the following have little penetrating power and are normally a hazard to health only in the form of internal radiation received through ingestion, inhalation, or open wounds?

Alpha particles

Factors that could determine the effect of radiation on the body include?

• rate of absorption

• Individual variability

• Nutrition, oxygen tension, metabolic state