Can Air Pollution Cause Diabetes?

New research has uncovered a direct link between poor air quality and a heightened risk of contracting diabetes, resulting in potentially millions of new diagnoses of the disease per year. Even more concerningly, the levels of pollution responsible for the increased risk are considerably below the level deemed “safe” by the World Health Organisation (WHO).

Alarming results

The study, published in the journal Lancet Planetary Health, focused on 1.7 million US army veterans with no previous history of diabetes and followed them over an average of 8.5 years. After allowing for pre-existing conditions which may have contributed to the contraction of diabetes and assessing the results through a series of computer models, the researchers then cross-referenced the veterans’ health against known pollution levels where they live and work.

The results showed that 21% of veterans who were exposed to between five and ten micrograms per cubic metre of particulate matter (PM) developed diabetes. However, those exposed to between 11.9 and 13.6 micrograms per cubic metre were at a 24% risk of contracting the disease. While a 3% increase might not sound substantial, it could translate to as much as 6,000 new cases of diabetes for every 100,000 residents. For reference, the WHO “safe” level is set at 12 micrograms per cubic metre.

Particulate matter a deadly pollutant

The new study reinforces other research linking PM2.5 to poor health. So named for the 2.5 micrometre diameter of the particles involved, PM2.5 is 30 times finer than a human hair and can infiltrate not only the lungs, but also the bloodstream. This makes it especially dangerous as it can reach all parts of the body and have long-term health implications for those exposed to it over a prolonged period.

Aside from the link with diabetes, PM2.5 is also thought to exacerbate a wide range of coronary and cardiovascular complaints, including heart disease and strokes, as well as asthma, cancer and premature aging. The new study is particularly concerning as it throws doubt on the previously held “safe” levels of PM2.5 concentration.

Developing world at elevated risk

The possibility of contracting diabetes appeared to rise in directly inverse proportion to the wealth and capability of a country to handle it adequately. Poorer nations such as Afghanistan, Guyana, India and Papua New Guinea, for example, are thought to be at a higher risk than developed nations like Finland, France and Iceland. Indeed, a report last year from The Lancet found that 92% of the nine million premature deaths caused by poor air quality occurred in developing countries.

Fortunately, awareness of the problem in these places is on the increase. There is a growing market for CEMS in developing countries, showing that the populace are becoming more cognisant of the risk. At the same time, governments are making slow moves towards a cleaner air policy; China and India have both suffered the ignominy of being the most polluted countries on Earth in recent times, but both are making strides to tackle the problem.