Researchers reviewing past studies say air pollution may contribute to the respiratory and allergic diseases like asthma, chronic obstructive pulmonary disease, pneumonia, and even tuberculosis.

The relationship between air pollution and respiratory disease is complex. However recent studies have shown an increased recognition that traffic-related air pollution and emissions from domestic and biomass fuels have had adverse effects on health, particularly in less developed nations

Robert Laumbach of the Robert Wood Johnson Medical School and Howard Kipen said in a report on Monday that newer methods for measuring and modeling exposure to pollutants have begun to “unravel complex associations with asthma and other respiratory tract diseases.”

The report that will be published in the January 2012 edition of the Journal of Allergy and Clinical Immunology showed that because a high degree of variability in personal exposure to pollutants, contact with air pollution from a variety of sources can largely be prevented.

“These studies indicate that air pollution from these sources is a major preventable cause of increased incidence and exacerbation of respiratory disease. Physicians can help to reduce the risk of adverse respiratory effects of exposure to biomass and traffic air pollutants by promoting awareness and supporting individual and community-level interventions,” the authors of the study wrote. 

Researchers indicated that there had been alarming global increases in the rates of asthma and chronic obstructive pulmonary disease over recent years, and researchers have launched more aggressive investigations into the role of biomass fuels (BMFs) and motor vehicles on public health. 

Most BMF exposure comes from burning organic materials such as wood, charcoal, dung, crops, and other raw plant materials for cooking or cleaning. Exposures to BMFs are exacerbated with open fires or traditional stove designs that do not have flues or hoods to suck emissions away from indoor areas.

However industrial “smokestacks” that burn fossil fuels are still the major source of outdoor air pollution. 

The authors said that although exposure to air pollution may sometimes be hard to control, the amount of harmful exposure to traffic pollution and BMFs can be controlled and adverse health effects can be reversed.

Pollution’s Links to Lungs, Asthma, and Infections

Past studies have shown that children living in more polluted areas have also shown to have reduced lung growth compared to children living in cleaner areas, and that moving to cleaner areas will improve lung growth, according to the report. 

Asthma is worsened on days with higher levels of ozone and other pollutants, and is often measured by visits to emergency rooms, researchers said.   However, more studies have designed more complex cohort methods to understand traffic-related pollutants and its role in the genesis or causation of asthma.

Studies have also shown that infants who were at a high familial risk for asthma who were exposed to more nitric oxide and small particulate matter were significantly more likely to develop asthma by seven.

A Swiss study also found that the hazard ratio for diagnosed asthma in adults also significantly increased as more as emissions and traffic pollution increased in a decade.

The World Health Organization reported that exposure to indoor air pollution doubles the risk of pneumonia and other acute lower respiratory tract infections, and could account for half of the 800,000 annual worldwide fatalities in children younger than 5 years old. 

According to past studies, biomass fuels increased the risk of pneumonia by nearly 200 percent, and increased the risk of acute respiratory tract infection by more than 300 percent in children.

A study examined a large sample of Indian households and found an increase in self-reported tuberculosis infection with more BMF use, but smoking was not accounted for in the study, and no studies have shown an association between traffic pollution and tuberculosis. 

More regulation and better medical advice need to be set in place to reduce the growing rates of respiratory diseases and asthma researchers concluded. 

“These risks need to be both incorporated into public policy and explored for their role in medical decision making at the individual level,” researchers wrote.