Mercury in Fish Mercury Is a Highly Toxic Metal Found in Neon Signs

question 258

Multiple Choice

Mercury in Fish
Mercury is a highly toxic metal found in neon signs, fluorescent lights, older thermometers, and certain kinds of telescopes. It can also be found in something that many people eat on a regular basis: fish. The mercury we might find in a can of tuna is most likely an indirect result of the coal industry. Mercury, which is naturally found in coal, is released into the air when coal is burned. It finds its way into waterways via mercury-laced rain.
Mercury accumulates in certain kinds of fish through a process called biomagnification. Biomagnification occurs when a substance enters the food chain in small amounts at the very bottom and then increases in concentration in animals higher up on the food chain. Once a fish eats another creature containing mercury, the mercury does not leave that fish's body but instead is stored in fat. Therefore, the mercury continually accumulates as more mercury-contaminated fish are eaten.
Despite the toxicity of mercury and the widespread nature of fish contamination, there is no need for the public to be overly apprehensive. Many popular fish, such as salmon, catfish, or tilapia, are generally safe to eat. Other fish, especially tuna and grouper, should only be eaten in moderation. Young children and pregnant women should be especially cautious about how many servings of mercury-contaminated fish they have per week. It is recommended that people in these groups not eat more than 2 servings of mercury-contaminated fish per week. Fish with the highest levels of mercury include shark, swordfish, and king mackerel. All people should avoid eating large amounts of these kinds of fish, and no one should eat these fish more frequently than once a month.
What is the purpose of the passage?

• A)To inform the reader of the process in which mercury accumulates in fish and provide information regarding consumption.
• B)To alert at-risk groups to limit their consumption of fish with the highest levels of mercury.
• C)To persuade people to re-evaluate the consumption of mercury-contaminated fish.
• D)To urge the reader to make a difference when it comes to environmental issues in the ecosystem.

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Definitions:

Sensory Structures

Components of an organism that are specialized to detect changes in the environment or within the organism itself.

Eating Habits

The patterns and practices associated with how organisms, especially humans, consume food, significantly impacting health, culture, and society.

Mollusks

Invertebrate animals with soft, unsegmented bodies, many of which have shells, such as snails and clams.