Obesity Linked to Inhalation of Air Pollutants

A new study suggests overweight or obese individuals breathe in up to 50 percent more air each day than those of a healthy weight, which makes the overweight or obese more vulnerable to air contaminants.

In the study, researchers from the School of Public Health at the University of Montreal analyzed information from 1,096 participants aged between 5 and 96 years who were obese or overweight, comparing that information with data collected from 902 participants of a normal, healthy weight. Adults were classified in 1 of 5 body mass index (BMI) groups: normal weight (18.5-<25 kg/m²); overweight (25-<30 kg/m²); obese class 1 (30-<35 kg/m²); obese class 2 (35-<40 kg/m²); and obese class 3 (40 kg/m² or more).

To gauge participants’ inhalation rates, investigators assessed urine samples by measuring disappearance rates of two ingested tracers—deuterium and heavy oxygen. The tracers were then used to measure the amount of carbon dioxide that each participant exhaled in real-life situations in their normal environment. This was measured every minute of the day from 7 days to 21 days.

Overall, researchers found that overweight and obese adults breathe in 7 percent to 50 percent more air every day, compared with adults of normal weight. In addition, overweight and obese children breathe in 10 percent to 24 percent more air each day than children of normal weight.

At 24.6 m³, obese class 2 individuals were found to have the highest average air inhalation, compared with 16.4 m³ among adults of normal weight. According to the researchers, this means obese class 2 individuals are breathing in 50 percent more air pollutants.

In light of these findings, Pierre Brochu, PhD, a professor in the school of public health at the University of Montreal and lead study author, advises primary care physicians to “inform obese [patients] that, by decreasing their body weight down to normal weight values, they should seriously reduce their risk of chronic diseases resulting from indoor and outdoor air pollutants.”

Indeed, the findings “may be used as an additional argument to encourage patients to change their habits in order to lose weight,” adds Sami Haddad, PhD, associate professor in the department of occupational and environmental health at the University of Montreal, and co-author of the study.

“Obesity is a risk factor for many diseases such as diabetes, coronary heart disease, some cancers (breast and colon), hypertension, dyslipidemia, stroke, liver diseases, sleep apnea, and infertility,” says Haddad.

“Increased risk of disease related to air pollution is an additional factor to add. If a patient is known to be exposed to significant levels of air contaminants and reducing weight is an avenue the patient cannot or will not pursue, then reducing exposure is another alternative to reducing risks,” he continues. “Reducing exposure can be achieved by reducing the levels of air contaminants, moving to a less contaminated environment, or using protective gear, such as filtered masks, if necessary.”

Reference

Brochu P, Bouchard M, et al. Physiological Daily Inhalation Rates for Health Risk Assessment in Overweight/Obese Children, Adults, and Elderly. Risk Analysis. 2013.