How Does Particulate Matter Impact Public Health?

The damaging impact that particulate matter – especially particulate matter 2.5 (PM2.5), which is 20 times finer than a human hair and as such can be easily inhaled and can even infiltrate the bloodstream – is well-documented. However, the exact effect that this kind of pollution has on human health in numerical terms is hard to define.

With that in mind, scientists from Columbia University in the United States have sifted through 16 years’ worth of data from 1999 to 2015 to try and come to a definitive conclusion regarding just deadly the contaminant is. Their findings demonstrated that while recent improvements in air quality have resulted in benefits for public health, PM2.5 still results in thousands of premature deaths each year.

Understanding before overcoming

The first step in tackling any problem is comprehending its full extent. Thanks to recent developments in the technology, particulate matter sensing for air quality measurements has allowed us to access greater and more precise information about the contaminants in our airways than ever before. The next step is to understand how this pollution impacts human health.

To do so, the study authors analysed population data from across the contiguous States between 1999 and 2015. This was cross-referenced against records of PM 2.5 concentrations for the same time period to determine how the latter affected the former. The results were then processed via the use of four Bayesian spatiotemporal models to determine how much of an impact PM2.5 had on public health, as well as how gradual improvements in air quality affected that metric.

The results showed that exposure to higher levels of PM2.5 resulted in higher mortality rates, especially in impoverished or lower-income areas. It also demonstrably proved that improvements in air quality contributed to public health benefits in the time period in question.

Low concentrations still dangerous

According to the findings of the report, even low concentrations of PM still had a noticeable impact on the death rate and on life expectancy. The minimum observed concentration was 2.8μg/m3. Tellingly, PM2.5 pollution which registered higher than that was considered directly responsible for the deaths of an estimated 14,757 males and 15,612 females.

At the same time, the pollution is believed to have lowered life expectancy in males by 0.13 years and by 0.15 years in females. As a general rule, the mortality rate rose and life expectancy decreased in places which suffered from adverse social conditions, such as lower income and higher instances of poverty. As a result, the researchers freely admit that their findings are subject to limitations in that they could not guarantee a causal link between the two phenomena. However, the research does point strongly towards the fact that PM2.5 has a massive impact on human health and that hypothesis is supported by falling mortality rates as the air quality has improved.

Of course, monitoring PM2.5 concentrations in an industrial setting, where workers may be exposed to harmful levels of pollution more frequently and consistently, is perhaps an even greater priority. The e-learning session Calibration and measurement of particulate at low concentrations provides a great reference point for those looking to learn more on the subject in an industrial context.