Black Carbon Exposure Raises Respiratory Risks in Mississippi, Study Finds

Black carbon, one of the major causes of air pollution, has been associated with an increase in respiratory-related hospitalizations in the state capital city of Jackson, based on a new study by the University of Mississippi. Released in Environmental Pollution, the study analyzed 2014–2015 data and points to the increasing health hazard of air pollution, especially for older people.

Black carbon or soot is a product of incomplete combustion from sources such as coal, diesel vehicles, wood fires, and industrial processes. It is a key component of PM2.5 – fine particle matter less than 2.5 microns in diameter – which can penetrate deep into lungs and even the bloodstream. PM2.5 is already recognized as a cause of numerous diseases, including respiratory disease, cancer, cardiovascular disease, and stroke.

The study, which was conducted by environmental toxicologist Dr. Courtney Roper, targeted Jackson because it recorded the highest concentration of black carbon ever in Mississippi. From the combination of Medicare data and air pollution monitoring, the study established that short-term exposure to black carbon had a direct association with heightened respiratory hospitalisation. There was a rise in hospital admissions for respiratory disease of 1.3% per every 1.42 micrograms per cubic metre increase in black carbon.

Above all, the study found that women and especially older women were also likely to be hospitalized due to this exposure. Although anatomical factors like narrower airways can likely play a part in this, the researchers found that more work would be needed to determine the gender difference.

Although PM2.5 was never strongly associated with hospitalisations over the course of the year, seasonal impact was found to be present. Higher hospitalisation of asthma during spring might be because of interaction with other inhaled irritants such as pollen or traffic fumes. Lower temperatures were also associated with lagged hospitalisation peaks, which might be due to indoor air quality problems during winter periods.

Dr. Hang Nguyen, a postdoctoral researcher who conducted the study, said that the study shows the effect that even small particles of black carbon in urban air can have on human health. The research also outlines the delay in health effects that certain weather patterns can create, adding to the difficulty of responding to pollution.

There are public health planning and policy implications where there is comparable socio-economic and environmental standing. Mississippi has been noted for healthcare access disparities, especially among vulnerable populations. It can be applied to inform focused intervention by being aware of the determinants of hospitalization in the environment.

Researchers intend to broaden the research to investigate cardiovascular health effects on air pollution. The second phase of the study will continue to be centered on Jackson, in order to target policy and community awareness within the surrounding area.

This study adds to the overall push for determining the human health impacts of environmental pollution, particularly in understudied areas such as Mississippi. With environmental justice and unequal pollution exposures for low-income communities now a priority, this study provides vital information to the national debate.