Air pollution

Who does air pollution affect the most?

Clean Air Student Council

Have you ever seen foggy layers of smoke or felt the need to cough near cars or factories? Every one of us is susceptible to the negative impacts of air pollution. In fact, air pollution is now the most powerful environmental “serial killer” for early death, “murdering” around 7 million people every year from exposure to fine particles in polluted air that penetrate deep into the lungs and cardiovascular system, causing diseases including stroke, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections, including pneumonia[1]. That’s more than the deaths from AIDS, tuberculosis and malaria combined! People’s health risks from air pollution vary widely depending on age, where they live, their underlying health, and many other factors[2]. So, who does air pollution affect the most? 


Patients with chronic diseases


People with asthma: Exposure to air pollution might worsen their symptoms or trigger asthma attacks[3]. A study of young campers with moderate to severe asthma showed they were 40% more likely to have acute asthma episodes on high pollution summer days than on days with average pollution levels[4]. Air pollutants, such as particulate matter and ground-level ozone irritate the airways, making them swell and tighten up, causing shortness of breath, wheezing, coughing and other breathing problems. Found in smog or haze, ozone is notorious for reducing lung function, as well as making it more difficult for asthma patients to breathe deeply. On the other hand, particulate matter, found in haze, smoke and airborne dust, can easily pass through their noses and penetrate into their lungs, which makes asthma worse, reduces their lung function and leads to more asthma attacks[5]


People with lung disease, e.g. chronic bronchitis, emphysema, and chronic obstructive pulmonary disease (COPD): COPD is caused by exposure to pollutants that produce inflammation, an immunological response. It narrows the patient’s airways, which is irreversible. When the tiny air cells reach the end of the lung’s smallest passageways, it leads to the destruction of tissue or emphysema[6]


People with cardiovascular (heart) disease: Air pollutants can travel deep into one’s bloodstream through the lungs and to the heart. They damage one’s blood vessels by narrowing and hardening them, causing blood clots, increased blood pressure and strain on the heart muscle. It can also cause abnormal heart rhythms and potentially cause small changes to the structure of one’s heart. This damage increases the patient’s risk of events like a heart attack or stroke[7].


People with diabetes: Exposure to air pollutants is significantly associated with an increased risk of type 2 diabetes mellitus[8]. Air pollutants decrease a patient’s insulin sensitivity and reduce the production of insulin in overweight and obese children[8]. Also, smoke from wildfires could increase blood glucose, and if the high levels persist, can produce extremely high levels of ketones, leading to diabetic ketoacidosis, a serious and life-threatening complication that is more common in patients with type 1 diabetes than with type 2. People with diabetes are also more sensitive to fine particulate matter (PM 2.5) in smoke, especially in light of their high prevalence of heart disease[9]


Unborn babies/pregnant women


Exposure to high levels of air pollution over longer time periods (ie weeks to months) may be linked to adverse pregnancy outcomes such as reduced birth weight or preterm birth, resulting in very small bodies10, as contaminants in the air can cross the placenta, affecting the health of the placenta itself and disrupting the baby’s development. Preterm labour increases the risk of other problems, such as low birth weight, underdeveloped lungs in the baby, and death of the baby during or shortly after birth. One 2019 study assessed the effects of common pollutants, such as ozone, sulfur dioxide, nitrogen oxide, and nitrogen dioxide. It found a correlation between air pollution and preterm labour. The risk was highest during a subsequent pregnancy. Moreover, in more extreme cases, stillbirth (death of the baby late in pregnancy) can occur. High level of air pollutants also places health concerns in the parent, since exposure to air pollution can increase the risk of preeclampsia and high blood pressure of the parent. These complications can harm the parent and the baby, which may necessitate an early birth. Last but not least, exposure to air pollution may affect the lung development of some babies, especially in preterm labour, as their lungs are not fully functional when they are born[11]


Infants and young children (less than 18 years old)


According to the United Nations Children’s Fund, 17 million babies around the world are breathing toxic air[12]. Infants and young children are more vulnerable to air pollution than healthy adults as their airways are smaller and their lungs, immune and metabolic systems are still developing, hence, they breathe more rapidly than adults. Some children are especially more vulnerable, for example, children with underlying chronic lung conditions such as asthma and cystic fibrosis. If a child constantly is exposed to high levels of air pollution, they might even develop asthma during childhood or as an adult. If they already have asthma innately, their symptoms will be exacerbated. Wheezing and coughing are common symptoms. They may also have high risks of being diagnosed with lung cancer when they’re older or have infections like pneumonia. Last but not least, children are more active outdoors than adults and therefore breathe in higher doses of outdoor pollutants. Infant prams are often put by parents at the level of car exhausts and hand-held cigarettes, therefore, they are more prone to suffer from respiratory infections[13].


Elderly/older adults (over 65 years old)


Firstly, most elderly spend more time outside than younger adults, leading to increased exposure to outdoor air pollutants. As they grow older and older, their organs start to age faster and their body functions will start to deteriorate. Therefore, their bodies, in general, are less able to fend off inflammation and other damage from breathing air pollution. Particulate pollution, especially smog exposure, increases ER visits and causes premature death in older adults. In addition, long-term exposure to air pollution is associated with brain damage and a type of  “silent” stroke. Poor air quality also increases blood pressure and stiffs blood vessels, which increases the elderly’s risk of heart disease or stroke[14]


People in poverty


Pollution is strongly linked to poverty. Nearly 92% of pollution-related deaths occur in low- and middle-income countries, as they have fewer resources for healthcare as well as capital and technology to combat the adverse effects of air pollution. Pollution-related illnesses result in direct medical costs, costs to healthcare systems and opportunity costs resulting from lost productivity and economic growth[15]. Other than that, the unpleasant environment that most poor people live in is a risk factor for health concerns related to air pollution. In fact, most recorded air pollution-linked deaths occur in developing countries, where laws are weak or not applied, vehicle emission standards are less stringent and coal power stations are more prevalent. On the other hand, it’s often the poorest who live in cramped informal settlements, often near rubbish dumps, who feel the full force of air pollution in the big cities of developing countries. Take Nairobi in Kenya as an example: the huge smouldering dump site in Dandora on the eastern outskirts of the city lies right next to schools, churches, clinics and shops and frequently gives off toxic fumes, which affects the overall well-being and health of residents living in the downwind of the dump site, particularly small children[16]. Hongkongers also experience similar situations. According to a new study conducted by the University of Hong Kong, those who live in “socially deprived” areas of the city are more exposed to bad air than those in wealthier areas[17]


Non-white populations, especially blacks


The most recent EPA review of the research on the health effects of particle pollution concluded that nonwhite populations, especially blacks, faced higher risk from particle pollution, as they often face higher exposure to pollutants and may experience greater responses to such pollution. People who live in predominately black or African American communities or are blacks, Hispanics and Asians themselves, suffer a greater risk of premature death from particle pollution than those who live in communities that are predominately white or people who are white, while income did not drive the differences. Blacks who had higher income than whites still faced greater risk, suggesting that other factors such as chronic stress as a result of discrimination may also contribute to premature death. Other common factors, such as air pollutants from the traffic, also pose a greater health risk for African Americans. Due to decades of residential segregation, African Americans tend to live where there is greater exposure to air pollution[18], and this still hasn’t completely changed nowadays.