77659614e7b122d66d6575bc2943e12dAir pollution is the introduction of particulates,biological molecules, or other harmful materials into Earth's atmosphere, causing diseases, allergies, death to humans, damage to other living organisms such as animals and food crops, or the natural or built environment. Air pollution may come from anthropogenic or natural sources.

Air pollution has already been linked to health problems including asthma, bronchitis, lung cancer, heart disease and more. Now, a new study suggests that another ailment can be added to the list — obesity.

Epidemiologic evidence suggests that air pollution is a risk factor for childhood obesity. Limited experimental data have shown that early-life exposure to ambient particles either increases susceptibility to diet-induced weight gain in adulthood or increases insulin resistance, adiposity, and inflammation.

A study published in the Journal of the Federation of American Societies for Experimental Biology found that rats who breathed polluted Beijing air gained weight after just three weeks of exposure. They also experienced cardio-respiratory dysfunctions, and decreased metabolic function.

For the study, conducted by Duke University, US, researchers exposed rats to either samples of polluted air from Beijing or filtered air. They stayed nineteen days into the experiment, rats exposed to unfiltered air had 50 percent higher bad cholesterol levels, 46 percent higher triglycerides, and 97 percent higher total cholesterol, as well as a higher insulin resistance level.

While the rats ate the same amount of food throughout the study, the rats breathing unfiltered air also gained more weight eight weeks into the study, with female rats 10 percent heavier and male rats 18 percent heavier than their counterparts breathing clean air.

Researchers found the air caused metabolic dysfunction in rats, leading to obesity and the precursors of diabetes when compared to rats that had not been exposed to the air.

Since chronic inflammation is recognized as a factor contributing to obesity and since metabolic diseases such as diabetes and obesity are closely related, these findings provide clear evidence that chronic exposure to air pollution increases the risk for developing obesity.

Previous studies have shown air pollution causes oxidative stress-lipid oxidation and TLR2/4-dependent inflammation; a pivotal pathogen recognition receptor that has a key role in inflammation, diabetes, and injury in the organs and circulatory system, as well as an increased risk of death.

Researchers think that, if translated and verified in humans, these findings will support the urgent need to reduce air pollution, given the growing burden of obesity in today's highly polluted world.

On the other hand other researchers claim role of obesity in air pollution or carbon emission. They found that this happens because the fatter population needed 19% more food energy for its energy requirements. Researchers said :"The heavier our bodies become the harder it is to move about in them and the more dependent we become on cars." So they factored in greater car use by the overweight. Also meat production and food prepare causes 20% of global emissions.

So we do not know whether air pollution causes obesity or obesity is responsible for air pollution. This is matter of genetic ecology. Maybe the same applies for global warming and climate changes. They may have the same impact into the incidence of many diseases.

Of course there are potential solutions on the horizon, including the manufacture of building materials that would themselves eat smog and increase of green space in urban areas. Cities including Oslo are also contemplating a relatively near future in which they ban cars entirely. Let's hope these findings put more pressure on governments to fix this problem once and for all.



  1. http://www.upi.com/Health_News/2016/02/22/Study-Air-pollution-increases-risk-for-obesity-diabetes/6451456146674/,
  2. http://www.wired.co.uk/article/exposure-to-air-pollution-obesity,
  3. http://time.com/4233241/air-pollution-obesity-diabetes/,
  4. http://www.ibtimes.co.uk/air-pollution-increases-obesity-risk-urgent-action-needed-improve-air-quality-1545766,
  5. http://www.ncbi.nlm.nih.gov/pubmed/26891735.