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Vol. 11 No. 3 - July 2005

Air Pollution May Cause Lifelong Lung Deficits

By: Per Elvingson

By the age of 18, the lungs of many children who grow up in the polluted areas are underdeveloped and are unlikely ever to recover, according to the results of the Southern California Children’s Health Study, the longest investigation ever into air pollution and children’s health.

The study provides the most definitive evidence yet that routine exposure to dirty air during childhood actually harms lung development, leading to a permanently reduced ability to breathe. Underpowered lungs are known to cause a wide range of health problems.

Between 1993 and 2001, scientists have tracked levels of major pollutants in twelve Southern California communities while monitoring the pulmonary health of1,759 children as they progressed from 4th grade to 12th grade (10 to 18 years old).

The twelve communities included some of the most polluted areas in the greater Los Angeles basin, as well as several low-pollution sites outside the area.

Children breathing dirty air were nearly five times more likely than children in less polluted communities to grow up with weak lungs, they found. In the highest pollution areas 7.9 per cent of the 18-year-olds had lung capacities that were less than 80% of what they should have been. Among teenagers subjected to the least-polluted air, only 1.6 per cent had underperforming lungs. This is some of the most convincing evidence that air pollution has chronic effects.

The pollutants for which a correlation was found between concentration and deficits in lung development were nitrogen dioxide, acid vapour, particulate matter with a diameter of less than 2.5 microns and elemental carbon. The strongest correlation was observed with small particulates. These are pollutants that all derive from vehicle emissions and the combustion of fossil fuels.

The definition of clinically low lung function is when a person has less than 80 per cent of the lung function expected for his or her age. This is viewed as a significant deficit with both short and long-term implications.

If a child or young adult with low lung function were to have a cold, they might have more severe lung symptoms, or wheezing. They may have a longer disease course, while a child with better lung function may weather it much better.

Potential long-term effects are more alarming. Low lung function has been shown to be second only to smoking as a risk factor for all-cause mortality.

Lung function increases steadily as children grow, peaking at about age 18 in women and sometime in the early twenties in men. Lung function stays steady for a short time and then declines by 1 per cent a year throughout adulthood. As lung function decreases to low levels in later adulthood, the risk of respiratory diseases and heart attacks increases.

Researchers are unsure how air pollution may retard lung development. Chronic inflamma-tion may play a role, with air pollutants irritating small air ways on a daily basis. Scientists also suspect that pollutants might inhibit the growth of alveoli, the tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place.

The research team will continue to follow the study participants into their early twenties, when their lungs will mature and stop developing entirely. The team aims to find out if the participants begin to experience respiratory symptoms and if those who moved away from a polluted environment show benefits.

The Swedish NGO secretariat on Acid

Rain, Box 7005, 402 31 Goteborg,


(Source: Acid News, Sweden)

This article has been reproduced from the archives of EnviroNews - Newsletter of ISEB India.

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