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Population Data Biomonitoring - CDC Tracking Network

Environmental Chemicals

The environmental chemicals included on CDC's Tracking Network are listed to the right. They can enter the body in three main ways: through the air, water, and/or food. They are measured in blood and/or urine samples. The level of the chemical or its metabolite in the blood or urine depends largely on how much of the chemical has entered the body from eating, drinking, breathing, and skin contact. It also depends on what happens to the chemical in the body. Finding an environmental chemical in a person's blood or urine does not mean that it causes health effects or disease.


Arsenic

Arsenic is a naturally occurring element found in combination with other elements. It has two forms: organic and inorganic. Organic arsenic compounds are found mainly in fish and shellfish. In general, organic compounds are less harmful than inorganic arsenic. Inorganic arsenic compounds are found in soils, sediments, and groundwater.

The Tracking Network includes biomonitoring data on the concentrations of total arsenic—both organic and inorganic forms—in urine in NHANES participants aged 6 years and older. Urinary total arsenic levels reflect recent exposure. Finding a measurable amount of arsenic in urine does not mean that the level of arsenic causes a health effect.

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In addition to biomonitoring data on arsenic, the Tracking Network has information and data about arsenic in drinking water.

Benzene

Benzene belongs to a class of chemicals called volatile organic compounds (VOCs) that evaporate into the air easily. Most people are exposed to benzene mainly from gasoline fumes, automobile emissions, and cigarette smoke.

The Tracking Network includes biomonitoring data on the concentration of benzene in blood in NHANES participants ages 12 years and older. Levels of benzene in blood reflect recent exposure. Finding a measurable amount of benzene in blood does not mean that the level of benzene causes a health effect.

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Cadmium

Cadmium is a naturally occurring element. Most soil and rocks, including coal and mineral fertilizers, contain some cadmium. Cadmium is used in many products, including batteries. It is found in tobacco and tobacco smoke.

The Tracking Network includes biomonitoring data on concentrations of cadmium in blood and urine in NHANES participants ages 1 year and older (blood) and ages 6 years and older (urine). Blood cadmium reflects recent and accumulated exposure, while urine cadmium reflects accumulated exposure. Finding a measurable amount of cadmium in blood or urine does not mean that the level of cadmium causes a health effect.

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Chloroform

Chloroform is a colorless and unstable liquid. In the environment, chloroform is formed when chlorine reacts with natural organic materials found in water. Most of the chloroform found in the environment comes from adding chlorine to water.

The Tracking Network includes biomonitoring data on concentrations of chloroform in blood in NHANES participants aged 12 years and older. Levels of chloroform in blood reflect recent exposure. Finding a measurable amount of chloroform in blood does not mean that the level of chloroform causes a health effect.

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Cotinine

Cotinine is a chemical that a person's body makes when it breaks down nicotine. Nicotine is found in all tobacco products, including cigarettes, cigars, snuff, and chewing tobacco. The best way to show how much nicotine a person has been exposed to is measuring cotinine in a person's blood. This method is used for both smokers and non-smokers exposed to secondhand smoke.

The Tracking Network includes data on the concentration of cotinine in serum (a component of blood) in non-smoking NHANES participants aged 3 years and older. These results provide an estimate of secondhand smoke exposure in the U.S. population.

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Lead

Lead is a soft, dense, blue-gray metal that occurs naturally in the Earth's crust. Lead has been widely used in manufacturing and in many products, including paints, solder, glass and crystal, batteries, and metal alloys. Until the 1970's, lead was used in household paint; until the 1980's, lead was added to gasoline. Because of health concerns, lead is no longer added to gasoline or house paint. In the past, lead solder was used for sealing food cans in the United States but this is no longer done.

The Tracking Network includes data on the concentration of lead in blood in NHANES participants aged 1 year and older.

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In addition to biomonitoring data on lead, the Tracking Network has information and data about childhood lead poisoning.

Mercury

Mercury is an element that is found in air, water, and soil. It exists in three forms that have different properties and sources of exposure. The three forms are elemental mercury (also called metallic mercury), inorganic mercury compounds, and organic mercury compounds.

Microorganisms in water and soil can convert elemental and inorganic mercury into the organic mercury compound methylmercury. Methylmercury builds up in the food chain, most importantly in ocean fish that eat other fish, like shark, swordfish, and king mackerel.

The Tracking Network includes biomonitoring data on the concentration of mercury in blood and urine in NHANES participants ages 1 year and older (blood) and ages 6 years and older (urine). Total blood mercury is mainly a measure of methylmercury exposure. Mercury in the urine mainly consists of inorganic mercury. It is also a measure of elemental mercury exposure. Finding a measurable amount of mercury in blood or urine does not mean that the level of mercury causes a health effect.

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Naphthalene

Naphthalene is used as a moth repellent and in production of other chemicals, especially for making polyvinyl chloride (PVC) plastics. Burning tobacco, wood, or fossil fuels, such as petroleum and coal, produces naphthalene.

The Tracking Network includes biomonitoring data on the concentration of naphthalene metabolites, 1-hydroxynaphthalene (1-naphthol) and 2-hydroxynaphthalene (2-naphthol), in urine from NHANES participants aged 6 years and older. Levels of 1- and 2-naphthol in urine reflect recent exposure. Finding a measurable amount of 1- or 2-naphthol in the urine does not mean that the level of the chemical causes a health effect.

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Pyrene

Pyrene is one of a group of chemicals called polycyclic aromatic hydrocarbons (PAHs). PAHs are formed when coal, oil, gas, wood, garbage, or other organic substances such as tobacco and grilled meat are partly burned.

The Tracking Network includes biomonitoring data on the amount of the pyrene metabolite, 1-hydroxypyrene, measured in the urine of NHANES participants aged 6 years and older. Urinary 1-hydroxypyrene levels reflect recent exposure. Finding a measurable amount of 1-hydroxypyrene in urine does not mean that the level of 1-hydroxypyrene causes a health effect.

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Toluene

Toluene is a volatile organic compound (VOC) that evaporates in the air and has a distinctive smell. It occurs naturally in crude oil. It is used as a solvent and in chemical production, and small amounts are added to gasoline.

The Tracking Network includes biomonitoring data on the concentration of toluene in blood in NHANES participants aged 12 years and older. Levels of toluene in blood reflect recent exposure. Finding a measurable amount of toluene in blood does not mean that the level of toluene causes a health effect.

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Uranium

Uranium is a naturally occurring, weakly radioactive element. It is found in very small amounts in nature. Because uranium is found everywhere, people are exposed to it from small amounts in the air, water, food, and soil. Naturally occurring uranium can contaminate nearby drinking water sources and raise the normal uranium levels in water.

The Tracking Network includes biomonitoring data on the concentration of uranium in urine in NHANES participants aged 6 years and older. Levels of uranium in the urine reflect recent and long-term exposure.

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In addition to biomonitoring data on uranium, the Tracking Network has information and data about uranium in drinking water.

 
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