Health impacts: particles and coal dust

Particles

Exposure to air pollution––especially particles––is the second leading risk factor for mortality globally (behind only high blood pressure), contributing to approximately 8 million deaths each year. Particles are particularly harmful, with chronic exposure to particulates shortening our lives by 1–3 years. Chronic exposure to particles has also been linked to: increased risk of death from cardiovascular disease; significant damage to the small airways of the lungs; increased hospitalization for asthma attacks for children; slowed lung function growth in children and teenagers; increased risk of lower birth weights and infant mortality; elevated risk of developing type-2 diabetes; cognitive impacts, including links to dementia, Alzheimer’s Disease, and Parkinson’s Disease; and increased risk of mental health issues such as depression. Acute exposures to particles can also cause harm, including: death from respiratory and cardiovascular diseases and stroke; diminished lung function; increased mortality in infants and young children; inflammation of lung tissue, even in young healthy adults; increased hospitalization and emergency room visits for cardiovascular diseases, strokes, congestive heart failure, and due to acute respiratory illnesses; and increased hospitalization for asthma attacks among children.

The health impacts of particles are influenced by particle size, composition, and shape. Particles are regulated based on size, with size also affecting how deeply particulates penetrate into the human body and their health impacts. Large particles like dust (PM₁₀) deposit rapidly after inhalation, mostly settling into our upper respiratory tract. Fine particles (PM_2.5) reach the lower respiratory tract and lungs, and very-fine particles (PM₁) tend to settle deep in the lungs and alveoli, the tiny air sacs where oxygen and carbon dioxide are exchanged between the lungs and blood during breathing. Ultrafine particles (PM_0.1) are small enough to penetrate cell walls to enter the bloodstream. All else being equal, breathing dust is not thought to be as harmful to our health as is breathing in smaller particles; however, particles including dust can be composed of a wide variety of materials. These materials include oils, heavy metals, salts, and black carbon, also known as soot, which each cause different health impacts. There is evidence that the components of larger particles, including metals can translocate from the lungs to the bloodstream and reach the brain. Particle shape can also be important, as, in perhaps the most well known example of asbestos. Asbestos particles are long, thin fibers that, because of their shape, can become permanently lodged in the lungs, leading to lung cancer and mesothelioma.

Coal Dust

The majority of research on the health impacts of coal dust, which is a type of particulate matter, has come from studies on occupational exposures of coal miners. Miners’ inhalation exposure to coal dust has been shown to place them at an increased risk of developing coal workers’ pneumoconiosis (CWP), also known as coal miner’s lung or black lung disease, progressive massive fibrosis, lung cancer, decreased lung function, as well as other health impacts.

Coal dust typically contains high levels of toxic metals, including mercury (Hg), lead (Pb), arsenic (Ar), cadmium (Cd), as well as crystalline silica. These substances are harmful when inhaled or ingested and are known to cause cancer, fetal defects, and neurological damage, even at very low doses. Coal dust also contains high levels of transition metals, including iron (Fe), manganese (Mn), and copper (Cu) that in addition to some toxic heavy metals, can induce oxidative stress in our bodies. Because coal dust has high concentrations of metals, there is reason to believe it causes harm at exposures below PM_2.5 and PM₁₀ NAAQS.

There is a body of research identifying adverse health impacts on communities living near coal mines and areas of coal-related activities, particularly in Appalachia. Identified impacts include: higher rates of lung, kidney, and heart disease, even for people who never worked in a mine; worse adjusted health status and with higher rates of cardiopulmonary disease, chronic obstructive pulmonary disease (COPD), and hypertension; more days of self-rated poor physical and/or mental health and activity limitation; higher mortality, including from lung cancer; and a wide variety of more frequent birth defects.

Comparable studies have not been done to assess health impacts on residents living near coal export facilities in Hampton Roads. There are references to a 2005 study by the Peninsula Health District purported to show that Southeast Newport News residents visited the emergency room for asthma at a rate double that of both Newport News and Virginia on average. However, while this study continues to be cited in the literature and media, a copy of the document cannot be found. Interviews with residents of Southeast Newport News and Lambert’s Point indicate asthma and other respiratory health impacts are widespread and a major issue of community concern. One resident of Southeast Newport News, Uneita Scott, reported that her sister became sick from exposure to coal dust as a child: "Her diagnosis was a coal miner's lung so they had to amputate it for her to have a healthy life. At 14 years old, doctors verbatim said she had the lung of a 30-year-old that worked in the coal mines."