Turning around a sharp bend on a little country road, I came across this neglected barn.
They were late to leaf out and before they even finished, the leaves abruptly turned brown and shriveled up.
ENVIRONMENTAL PROTECTION AGENCY
PA420-R-99-013 - Final Report
"Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet Aircraft"
U.S. Environmental Protection Agency, April 1999.
Public Health and Aircraft Emissions:
Ultimately, EPA's principal concern in evaluating and controlling (jet fuel) emissions is the preservation of human health and, secondarily, the protection of public welfare (including protection against damage to crops, vegetation, animals, and buildings)...In particular, they have significant concerns regarding the effect of NOx on local and regional environments. Tropospheric NOx has multiple environmental quality impacts…contributing to ground-level O3 and PM, but also air toxic concentrations, excess nitrogen loads to sensitive water bodies, and acidification of sensitive ecosystems (EPA 1997a)." (PM = Particulate Matter).
Table 1.1 Representative health effects of air pollutants
Jet Emission Pollutants:
- Ozone: Lung function impairment, effects on exercise performance, increased airway responsiveness, increased susceptibility to respiratory infection, increased hospital admissions and emergency room visits, pulmonary inflammation and lung structure damage. (Examples of these effects are chronic inflammation and structural damage to lung tissue as well as accelerated decline in baseline lung function).
- Carbon Monoxide: Cardiovascular effects, especially in those persons with heart conditions. Effects on animals are similar to humans.
- Nitrogen Oxides: Lung irritation and lower resistance to respiratory infections. Premature mortality, aggravation of respiratory and cardiovascular disease, changes in lung function and increased respiratory symptoms, changes to lung tissues and structure, and altered respiratory defense mechanisms. (Asthmatics are especially sensitive).
- Volatile Organic Compounds: Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment.
Table 1.2 Representative Environmental Effects
- Ozone: Crop damage, damage to trees and decreased resistance to disease for both crops and other plants. (Ground-level ozone interferes with the ability of plants to produce and store food so that growth, reproduction and overall plant health are compromised. By weakening trees and other plants, ozone can make plants more susceptible to disease, insect attacks, and harsh weather. Ground level ozone can also kill or damage leaves so that they fall off the plants too soon or become spotted and brown ...).
- Nitrogen Oxides: Acid rain, visibility degradation, particle formation, contribution towards ozone formation. NO2 is an important precursor to both ozone and acidic precipitation, which harms both terrestrial and aquatic ecosystems. NOx also plays a role in the formation of acid rain. Acid rain causes surface water acidification and damages trees. NOx contributes to the formation of particles in the atmosphere with the resulting health and visibility effects.
- Particulate Matter: Visibility degradation and safety effects for aircraft from reduced visibility. (PM is the generic term for a broad class of chemically and physically diverse substances that exist as discrete particles over a wide range of sizes. PM may either be emitted directly or formed in the atmosphere by the transformations of gaseous emissions of compounds including NOx, VOCs and sulfur oxides SOx. In addition to the evidence found for health effects associated with aggravation of asthma and increased respiratory illness, and that they may be chronic health effects associated with long-term exposure to high concentrations of coarse particles (FR, July 18, 1997).
"...the nature of the effects that have been reported to be associated with ambient PM, including premature mortality, aggravation of respiratory and cardiovascular disease…change in lung function and increased respiratory symptoms, changes to lung tissues and structure, and altered respiratory defense mechanisms; and sensitive sub-populations that appear to be at greater risk to such effects, specifically individuals with respiratory disease, cardiovascular disease and the elderly, children, asthmatic children and adults".
- Volatile Organic Compounds: Contribution towards ozone formation, odors, and some direct effect on buildings and plants. (They can arise from evaporation or incomplete fuel combustion. As a class, VOCs react with NOx in the atmosphere to form ozone, but individual VOCs may have additional health effects. Some VOCs have little or no known direct health effect, while other VOCs, such as benzene, are carcinogens. Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At high levels, VOCs can have a damaging effect on plants. VOCs that contain chlorine can also contribute to stratospheric ozone depletion).