HW315 Chapter 15: “Global Perspectives on Environmental Health” Flashcards
What was the issue with mink reproduction in 1980 Japan?
No other animals in the area exhibited the same response as the mink did. PCBs from a heat transfer agent in transformers contaminated the great lakes. Salmon then stored it in their fat which was largely present in the mink’s diet leading to reproductive issues.
What about the issue of cats showing staggered gait from neurotoxicities in Japan in 1950s?
Minimata disease was methyl mercury poisoning. This was caused by a chemical plant dumping methyl mercury in the Minimata Bay. The fish then stored this chemical in their fat. The cats ate this fish and showed symptoms. Humans also showed symptoms. It was even more evident when Japan shipped grain to Iran where the symptoms existed.
Why is selenium a good example of how chemicals can have two effects?
Selenium is important in the diet. It is normally consumed as the sulfur amino acids, methionine and cysteine. A deficiency is characterized by cardiomyopathy and muscle pain while an excess can cause characteristic neurotoxicities.
What is a good example of Vitamin A in excess, a essential fat-soluble vitamin?
Artic explorers and eskimos have seen an excess consumption when eating polar bear liver. The liver is saturated in vitamin A because of their diet of mostly fish. Vitamin A in excess effects the skin, mucous membrane and other systems while a deficiency can cause night blindness and connective tissue disorders.
How is an environment defined?
The environment is defined as the air we breathe, the water we drink, and the food we eat.
How is an environmental agent defined?
An environmental agent is the chemical or infectious agent or radiation source that is alleged to induce an environmental health incident.
What are the two critical characteristics of an environmental agent?
The quality of data linking the agent with the effect is important.
Second, there must be an analytical technique for the agent in question.
How is an adverse health effect defined?
An adverse health effect is usually defined in preclinical toxicology as any significant deviation from the norm.
What is a good example of an adverse health effect in the human population?
Hypnotics are safe and effective in large doses. Sleep induction is a therapeutic response. However, in the manufacturing environment, they may cause workers to fall asleep on the job; this is an adverse outcome. As this example demonstrates, the definition of adverse health effect is subjective.
How is risk defined?
Risk is the probability that an adverse outcome will occur. The opposite of individual risk is population risk—the expected number or percentage of adversely affected individuals in a population who will suffer an adverse outcome.
What are the three components to risk?
Risk has three components: exposure, causation, and dose-response.
Why is ecology important when dealing with environmental concerns?
There are normally second and third order of effects that may not seem obvious.
How is toxicology defined?
Toxicology is the study of the adverse effects of materials, chemicals, or radiation on living organisms. Although not explicit in the definition, what makes a toxicologist different from other scientists is that a toxicologist relates dose and response rather than just studying response.
How do the terms “statistical significance” and “toxicological significance” relate to different levels of findings?
The former is dependent on characteristics of the assay and the sample size, while the latter deals with hazards.
How is intrinsic activity defined?
Intrinsic activity can be defined as the maximum response that can be induced by a toxicant. Intrinsic activity is a biological property of a substance.
