Section 8: Environmental Health

Question 0

What are fecal coliforms

Answer 0

Gram negative, lactose fermenting, facultative microbes that produce gas

Question 1

What does BOD stand for and what is it

Answer 1

Biochemical oxygen demand

• assesses the quantity of oxygen needed by microbes in water
• high BOD results in the aging of a body of water, called eutrophication

Question 2

What is the goal of coliform testing

Answer 2

number of zero in drinking water

-water treatment systems are tested between 1-480 times a month

Question 3

What is the goal of water treatment

Answer 3

reduce the levels of BOD

Question 4

What is primary sewage treatment

Answer 4

• physical process
• removal of about 50% of solids in sedimentation tanks
• remaining is effluent, reduced BOD by 25%

Question 5

What is secondary sewage treatment

Answer 5

• Biological process
• Trickling filter
• Activated sludge process

Question 6

How does a trickling filter work

Answer 6

• effluent sprayed over rocks. Organic materials adheres to stone and is digested by microbes present in tank
• often used in smaller treatment plants

Question 7

What is an activated sludge process

Answer 7

• slime forming bacteria added to effluent and stirred in aeration tank. Bacteria digest remaining organic materia forming flotsam, significant reduction in BOD (95%)
• following aeration, water is treated chemically or with UV light and release

Question 8

What is tertiary sewage treatment

Answer 8

• expensive
• add lime or alum to remove nitrates and phosphates
• may also involve filtration
• tertiary effluent is then dechlorinated by aeration as it flows down a series of steps

Question 9

What are septic tanks

Answer 9

• Individual sewage treatment systems
• anaerobic digestion of organic material
• effluent overflows into drain field of soil or gravel and further digestion by aerobic microbes
• only effective for small amounts of sewage

Question 10

Who assigns letter grades to milk and who did previously

Answer 10

Previously graded by USPHS now done by the USDA

Question 11

What is pasteurization

Answer 11

originally 30 minutes at 62 degrees, now 72degrees for 15secs.

Question 12

What is a phosphatase test

Answer 12

enzyme should be destroyed by pasteurization treatment.

Question 13

What does chiropractic involvement in public health allow chiropractors to do

Answer 13

• promote preventative health care
• participate in public health effort
• interact with a variety of other healthcare professions
• work within health care system used evidence based approach
• evaluate and design clinical trials
• recognize individuals at risk