Assignment
1. Below is a list of chemicals with their oral LD50 in mg/kg (rats). Select the substance that is MOST toxic to rats.
DDT, 87 mg/kg
malathion, 885 mg/kg
carbaryl (sevin), 307 mg/kg
parathion, 3 mg/kg
2. Aflatoxins are natural chemicals found in certain forms of mold that can grow on rice, grains, nuts and seeds, legumes, and spices like black pepper. Continued exposure to aflatoxins has been linked to liver damage in some individuals. What do you call a substance that can cause liver damage?
Nephrotoxicant
Irritant
Hemotoxicant
Hepatotoxicant
3. Common forms of biological warfare agents are infectious pathogens and toxins. Which pathogen or toxin is characterized by shortness of breath, chest tightness, fever, cough, and low blood pressure within eight hours of its initial assimilation in the body or death within 36 to 72 hours?
Burkholderia mallei
Poxvirus variola
Ricin
Anthrax
4. Atrazine is one of the most widely used agricultural pesticides in the U.S. that may be applied before and after planting to control broadleaf and grassy weeds. It is used primarily on corn, sorghum, sugarcane, Christmas trees, and other crops. If the oral LD50 of Atrazine is 2,000 mg/kg, what is the oral lethal dose in ounces of this pesticide for a 190-lb pesticide applicator?
12
8
6
4
5. The OSHA regulation at 29 C.F.R. §1910.1000(d) requires employers to determine the cumulative exposure of workers to certain gases over an 8-hr work shift using the following formula:
E = CaTa + CbTb + .... + CnTn
8
E is the equivalent exposure for the work shift,
C is the concentration during any period of time in which the concentration remains constant, and
T is the duration of time in hours of the exposure.
The regulation further stipulates that no employee can be further exposed to the gas when the value of E exceeds the 8-hr time-weighted average limit set for the given substance. If a worker is exposed to ammonia concentrations throughout the workday as follows, 125 ppm for 4 hr; 75 ppm for 2 hr; and 25 ppm for 2 hr, determine the equivalent exposure (E):
28.
75.
88.
90.