Air pollution: The invisible health threat

Abstract

What is air pollution, and why does it matter to me? Air pollution is caused by gases and particles emitted by a variety of human activities and natural sources.[1] Over 99% of people breathe unsafe air. Air pollution is the most important health issue of our time, and it can cause heart and lung diseases, lung cancer, stroke and more.[1,2] It also harms our natural environment, decreasing the oxygen supply in our oceans, making it harder for plants to grow and contributing to the climate crisis. But air pollution is preventable. Solutions are available and must be implemented. Air pollution is a public health emergency Each day, as we take a breath, an invisible storm of particles and molecules infiltrates our bodies, posing a threat not only to our lungs but more than that. Air pollution is a major environmental threat and one of the main cases of death among all risk factors, ranking just below hypertension, tobacco smoking and high glucose.[1–3] WHO estimates that, globally, air pollution is responsible for about 7 million premature deaths per year from ischemic heart disease, stroke, chronic obstructive pulmonary disease and lung cancer, and also from acute respiratory infections such as pneumonia which mainly affects children in low- and middle-income countries. Being recognized as one of the main risk factors for non-communicable diseases, air pollution health effects also include preterm and low-birth weight, asthma as well as cognitive and neurological impairment basically having the potential to impact our whole body, way beyond our lungs. Five most dangerous pollutants in our air are: (i) PM2.5: PM2.5 refers to fine particles that are 2.5 microns or less in diameter. They are invisible to the naked eye, though noticeable as particle smog in highly polluted areas, and present indoors and outdoors. PM2.5 particles come from combusting unclean fuels for cooking or heating, burning waste and agriculture residue, industrial activities, transportation and windblown dust, among other sources. (ii) Ground-level ozone: Ground-level ozone, or tropospheric ozone, is a short-lived climate pollutant and although it exists only for a few days to a few weeks, it is a strong greenhouse gas. It forms when pollutants from industry, traffic, waste and energy production interact in the presence of sunlight. It contributes to smog, worsens bronchitis and emphysema, triggers asthma, damages lung tissue and reduces crop productivity. = (iii) Nitrogen: NO2 is the most harmful of these compounds and is generated from the combustion of fuel engines and industry. It can damage the human heart and lungs and it reduces atmospheric visibility at high concentrations. Finally, it is a critical precursor to the formation of ground-level ozone. (iv) Black Carbon: Black carbon, or soot, is a component of PM2.5 and is a short-lived climate pollutant. Agricultural burning to clear land, and the wildfires that sometimes result, are the world’s largest sources of black carbon. It also comes from diesel engines, burning trash, and stoves and furnaces that combust fossil and biomass fuels. Black carbon warms the atmosphere because it is very effective at absorbing light. It exacerbates warming of the air and surfaces in regions where it is concentrated, altering weather patterns and ecosystem cycles. (v) Methane: Methane comes mainly from agriculture, particularly livestock, sewage and solid waste, and oil and gas production. It helps create ground-level ozone and hence contributes to chronic respiratory illnesses and premature death. Five sectors are the main sources of human-driven air pollution. Good policies and practices can significantly reduce emissions from each sector.[3,4] (i) Agriculture Methane, generated from agricultural processes and livestock, contributes to ground-level ozone air pollution, causing asthma and other respiratory illnesses. Methane is also a powerful greenhouse gas that has contributed to as much as 45 per cent of current net-global warming. Open burning to clear agricultural fields and land is a leading contributor of particulate pollution including black carbon. (ii) Transport Fine particulate matter including black carbon, ozone and nitrogen dioxide are all linked to emissions from the global transport sector. Exposure to vehicle emissions is linked to up to 400,000 premature deaths a year and approximately US$1 trillion in health damages. (iii) Households Particulate matter including black carbon, carbon monoxide, lead and mercury are the main pollutants from burning solid fuels in open fires and inefficient stoves inside homes. (iv) Industry Industries release large amounts of carbon monoxide, hydrocarbons, particulate matter and chemicals into the air. (v) Waste The open burning of waste releases methane, particulate matter, persistent organic pollutants and other toxins. These enter the food chain and ecosystems, threatening human and environmental health. Way forward Everyone everywhere must come together For Clean Air.[5] Alongside celebrities, influencers and creators, everyone is invited to consider, commit and announce to your family, friends, peers and larger networks on social media to participate in this important mission for humanity and our earth. The contributions can be at individual level, civil society level, school level, local government level, corporate level and at the level of international agencies. The key areas to focus should include: reducing waste, recycling non organic trash, avoid solid waste burning, use clean non fossil fuels, use of more energy efficient appliances, using less polluting public transportation, car pooling, cycling or walking, steer investment to renewable and cleaner electricity generation, and reduce methane emissions thus reducing ozone pollution. Celebrate WORLD CLEAN AIR DAY: Use this day as an opportunity to improve public knowledge and actions to address the issue of air pollution. The Day can be used as platform for students and education officials to lead the fight for cleaner air and ask their governments and schools to transition to cleaner energy.