Pollutants

Health and Environmental Effects

Carbon Monoxide
(CO)

CO reduces the ability of the blood to carry oxygen, and is particularly dangerous to smokers, persons with heart disease, and those with anemia or heart disease. CO can also cause permanent damage to the nervous system.

Carbon Dioxide
(CO₂)

CO₂ does not directly impair human health, but is the most significant greenhouse gas that contributes to global warming. The effects of global warming are uncertain, but they potentially include disruption of global weather patterns and ecosystems, flooding, severe storms, and droughts.

Nitrous Oxides
(NO_x)

• NO_x exacerbate asthma, reduce lung function, and can lead to chronic lung damage. NOx also increases the susceptibility of young children and the elderly to respiratory infections.
• NO_x also reacts in the presence of VOCs and sunlight to form ground-level ozone, a major component of smog. Ozone irritates the eyes, damages the lungs, and aggravates respiratory problems. It is our most widespread and intractable urban air pollution problem. Ozone also reduces agricultural production and the growth rate of trees.
• NO_x contribute to the formation of acid rain. Acid rain acidifies the soils and waters where it falls, killing plants, fish, and the animals that depend on them. Acid rain also causes property damage through the corrosion of buildings and monuments.
• NO_x also contributes to nitrification (i.e., over-fertilization) of wetlands and bays, leading to algae blooms and fish kills.

Volatile Organic Compounds
(VOC)

• VOCs react in the presence of nitrogen oxides and sunlight to form ground-level ozone, a major component of smog. Ozone irritates the eyes, damages the lungs, and aggravates respiratory problems. It is our most widespread and intractable urban air pollution problem. Ozone also reduces agricultural production and the growth rate of trees.
• A number of exhaust VOCs are also toxic, with the potential to cause cancer, nerve damage, and other health effects. Benzene, a known human carcinogen, is an example of a toxic VOC found in vehicle exhaust.

Particulate Matter
(PM)

• PM causes lung problems, from shortness of breath to worsening of respiratory and cardiovascular disease, damage to lung tissues, and cancer. People of highest risk of these effects include asthmatics, individuals with chronic heart or lung disease, as well as children and the elderly.
• Ultrafine PM easily makes its way past the upper airway, and penetrates into the deepest tissues of the lungs, where accumulation can occur. These particles, and the chemicals sorbed to their surface, can then enter the blood stream; many of the chemicals are recognized human toxicants, carcinogens, reproductive hazards, or endocrine disruptors.
• PM decreases visibility, and causes aesthetic damage to buildings

Sulfur Dioxide
(SO₂)

• SO₂ aggravates existing respiratory conditions such as asthma and chronic bronchitis, increasing cough and mucous secretion.
• SO₂ also contributes to the formation of acid rain. Acid rain acidifies the soils and waters where it falls, killing the plants, fish, and animals that depend on them. Acid rain also causes property damage through the corrosion of buildings and monuments.