A new study published in the British Medical Journal (BMJ) finds a link between short-term exposure to PM 2.5 particles and the possibilities of contracting diseases such as septicaemia, fluid and electrolyte disorders, acute and non-specific renal failure and intestinal obstruction without hernia. The term fine particles (PM) refers to tiny particles or droplets in the air that are two and one half microns or less in width. They are often present in the air and come mainly from the combustion of diesel.
These particles are so fine that it can travel to the lungs and into the bloodstream. For this reason, PM 2.5 has been associated with respiratory and cardiovascular diseases. A study conducted in 1993, showed a clear association between PM 2.5 in the air and mortality rates in six US cities. The study published on November 27, 2019 in BMJ goes further and has found evidence of its relationship with other pathologies that are neither respiratory nor cardiovascular.
There was more than 95 million hospital admissions that occurred between 2000 and 2012, in the United States, among beneficiaries of Medicare health insurance. They found that several groups of prevalent but rarely studied diseases were associated with short-term exposure to PM 2.5.
In a more recent study, the relationship between PM 2.5 and hospitalisation was studies and the results showed that for each increase of one microgram of PM 2.5 the increase in hospitalisation did not rise more than 1% - even for the more common diseases.
Limitations of the study
This study has been conducted on people 65 years of age and older, certain ethnic groups, and people with low incomes who enjoy Medicare health insurance. Therefore, as the researchers indicate, caution should be exercised when extrapolating the results to the world population.
They also point out that people with low incomes as well as ethnic minorities tend to be more affected than others by equivalent exposure to PM, in addition to being more exposed both nationally and internationally.
Another point to keep in mind is that people who are more frail in health or who have chronic illnesses and who are often older people, such as those in the study, are more susceptible to illness.
Regardless of the above limitations, the study emphasises the importance of reducing contaminant concentrations to reduce the incidence of diseases that have been shown to be associated with PM and other contaminants.