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National Ambient Air Quality Standards (NAAQS): Standards set by the EPA for all criteria pollutants. EPA has established primary standards to protect public health and secondary standards to protect other aspects of public welfare, such as preventing materials damage, preventing crop and vegetation damage, or assuring visibility.

Nitrate: A compound containing nitrogen that can exist in the atmosphere or as a dissolved gas in water and which can have harmful effects on humans and animals. Nitrates in water can cause severe illness in infants and domestic animals. A plant nutrient and inorganic fertilizer, nitrate is found in septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps.

Nitrogen oxide: A criteria air pollutant. Nitrogen oxides (collectively known as NOx) are produced from burning fossil fuels, including gasoline and coal. Nitrogen oxides react with volatile organic compounds to form smog. Nitrogen oxides are also major components of acid rain. They may be harmful to the lungs and aggravate asthmatic symptoms.

Nonattainment area: A geographic area of the United States in which the level of a criteria air pollutant persistently exceeds the level allowed by the National Ambient Air Quality Standards (NAAQS). An area may have acceptable levels of one criteria air pollutant but unacceptable levels of one or more other criteria air pollutants; thus, an area can be both attainment and nonattainment at the same time. It has been estimated that 60% of Americans live in nonattainment areas.


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Obesity: Obesity in adults is defined as body Mass Index > 30. Body Mass index (BMI) is calculated using a person’s weight and height.

Outcome: The possible or likely result of an activity or process.

Overlay: Placing a layer of information on top of another layer to see how they are related.

Ozone (O3): A criteria air pollutant. Ozone is a variety of the oxygen molecule that consists of three atoms of oxygen instead of the more common two atoms. It occurs in nature, for example, when lightning strikes. Ozone is also formed by a chemical reaction of nitrogen oxides and volatile organic compounds together with sunlight and warm temperatures. In the upper atmosphere, high concentrations of ozone act to shield the Earth from harmful ultraviolet radiation from the sun. Holes in the ozone layer allow excess radiation to reach the Earth's surface, which increases the risk of skin cancer in humans. At ground-level, ozone is often referred to as smog. Breathing too much ozone can damage lung tissue and aggravate respiratory problems like asthma and emphysema. High ozone levels are also harmful to plants, crops, and trees, as well as to materials like rubber and paints. Ozone is a widespread and serious urban air pollution problem.

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New Hampshire Environmental Public
Health Tracking Program
NH Department of Health and Human Services,
Division of Public Health Services
29 Hazen Drive  |  Concord, NH 03301
(603) 271-4988  |  (800) 852-3345 ext.4988