Kidneys and Metals Problem Set

Problem 4: Sources of metals in the environment

For help to answer the question:

A.	a technician working on a computer component board assembly line
B.	a person who drinks water from a ground water well
C.	a person smoking a cigarette
D.	a person working on a new home computer
E.	a painter renovating an 100 year old home

Tutorial

Metals occur in nature in rock formations, and are all around us in our environment. Most people are usually not exposed to metals, but sometimes, metal exposures do occur. For example, arsenic is sometimes found in drinking water that comes from a ground water source. It gets into the ground water by the normal process of leaching out of rocks and soil. Arsenic can be toxic to humans and is associated lung cancer and skin cancer.

Cadmium and human activities

Many metals exposures are due to human activities. For example, almost everyone is occasionally exposed to cigarette smoke. Did you know that cigarette smoke contains cadmium, a potentially toxic metal? Cadmium is also found in lead and zinc ores. Symptoms of cadmium poisoning include nausea and vomiting, and if inhaled, lung lesions and chronic bronchitis.

Lead-based paint

Another common source of metals in our environment is old paint. Paint applied before 1973 is very likely to contain lead, a toxic metal. If the old paint is chipping, people can be exposed to the lead in the paint chips and paint dust. Lead poisoning can result in a wide range of symptoms from weakness and loss of appetite to coma and death in very acute or massive exposures.

Metals in computers

The semiconductor industry uses many types of metals. Semiconductors are parts of personal computers. During the manufacturing process, toxic metals are often created as by products. There is no exposure from the use of the finished product.

Mercury in fish

Some people have been exposed to mercury in the fish that they eat. Many of the fish in the Great Lakes region of the United States are contaminated with methyl mercury. People are often requested to limit their intake of fish from these lakes. Mercury got into the lakes from air contaminated by the smokestacks of coal-burning power plants, waste incinerators, and factories. Bacteria in the lakes convert many forms of mercury into methyl mercury which can be concentrated in fish. Mercury is a "neurotoxin." It damages the brain and nervous system. Symptoms include weakness, fatigue, not being able to concentrate, headaches, tremors in the hands, and memory loss. Even more severe symptoms are possible.