Peril to Young : UCI Researchers Find Children Suffer Most From Air Pollution

Children face a far greater health risk from air pollution than adults do, according to researchers at UC Irvine.

The results of a two-year study, released Friday, showed for the first time that children may take in up to six times more airborne pollutants than do adults exposed for the same period of time.

“It has been assumed that children, the elderly and the ill are more susceptible to air pollution,” said Robert Phalen, director of the UCI Air Pollution Health Effects Laboratory. “(But) I don’t think it has been known that children receive much higher doses than adults. It is quite likely that children are going to suffer more than adults.”

Phalen said the conclusions, based on computer-modeling techniques and castings of human air passages, suggest that infants face the most serious health risk from airborne pollutants.

The $150,000 research project used silicon rubber replicas of the air passages of 20 subjects ranging in age from 11 days to 21 years, all from victims who had died as a result of accidents or diseases that did not damage the lung.

Tests on these model air passages simulated low, moderate and heavy levels of physical activity in the presence of air pollutants, ranging from small lead particles from automotive fuel to large pollen particles.

Researchers then calculated the amount of pollutants that would be deposited in the subject’s lung per unit of body weight.

Children actually breathe more air per unit of body weight than adults to maintain body temperature and metabolic rates, Phalen said. In addition, the developing lungs of a child--especially an infant--are smaller and have far fewer air sacs, or alveoli.

The research was focused on the tracheobronchial region of the lung, the main windpipe branches that supply oxygen to the several air passages of the lungs. Phalen said pollutants tend to deposit at the junction of branching air passages. That junction is where a large proportion of lung cancers are found and the area that is constricted in asthma cases.

“It is important for epidemiologists to start targeting their studies more heavily toward children,” Phalen said.

The results of the study, funded by the California Air Resources Board, were published in the August issue of the scientific journal, Anatomical Record.