Air Pollution: Who Suffers Most?

Many people are sensitive to air pollution, and this sensitivity varies from person to person. The Air Quality Index (AQI) is a useful tool for understanding air quality and its potential health effects. When AQI values exceed 100, the air quality is considered unhealthy for sensitive groups, which include people with heart and lung diseases, older adults, children, people with diabetes, and those of lower socioeconomic status. Additionally, certain demographic groups, such as the elderly, pregnant women, and people with pre-existing conditions, may be at increased risk of experiencing harmful effects from air pollution exposure. These groups should be particularly cautious when planning outdoor activities by monitoring the AQI and taking necessary precautions to minimize their exposure to harmful pollutants.

People with heart or lung disease

People with heart disease are at a higher risk of cardiovascular events due to air pollution. The risk is associated with both short- and long-term exposure to particulate matter. Exposure to air pollution can also prematurely age blood vessels and contribute to a more rapid buildup of calcium in the coronary artery. This increases the risk of atherosclerosis, which is the build-up of fats, cholesterol, and other substances in the arteries.

People with ischemic heart disease, congestive heart failure, or arrhythmias are especially vulnerable to the adverse effects of air pollution on cardiovascular health. The American Heart Association reports that someone dies from cardiovascular disease every 40 seconds in the United States. Doctors often advise patients with heart disease to exercise more, eat healthily, and quit smoking to lower their cardiovascular risk. However, it is important to also consider air pollution exposure as a factor impacting heart health.

Air pollution can also induce and aggravate lung diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Particulate matter, nitrogen dioxide, ozone, and sulfur dioxide are particularly damaging forms of air pollution that can affect the lungs. Ozone, for example, can cause coughing, breathing difficulties, and lung damage. People with asthma may experience more symptoms and need to use their reliever inhalers more frequently when pollution levels are high.

Additionally, air pollution increases the risk of lung infections such as pneumonia and bronchitis. Prolonged exposure to air pollution can also cause lung conditions, including asthma and COPD. People with COPD may experience more frequent exacerbations and hospital admissions when exposed to particle pollution. In some cases, exposure to particle pollution has also been linked to higher mortality rates in COPD patients.

Diabetics

Several studies have found a strong link between air pollution and an increased risk of type 2 diabetes. While the exact mechanism behind this relationship has not yet been proven, scientists know that some pollutants can enter the bloodstream and interact with tissues and organs after being inhaled. These interactions can disrupt the body and alter insulin sensitivity and production, leading to an increased risk of type 2 diabetes.

The risk of pollution-related diabetes is higher in lower-income countries that lack clean air policies, such as India, China, and Indonesia. In contrast, more wealthy countries, such as Canada, Australia, and New Zealand, have a lower risk. This may be due to the higher levels of air pollution found in low-income cities, as more than 80% of people living in urban areas breathe air that does not meet the World Health Organization (WHO) guidelines.

Additionally, air pollution is causally related to traffic and emission conditions, which can decrease physical activity levels. Decreased physical activity is inversely related to insulin resistance and type 2 diabetes. Therefore, the relationship between air pollution and type 2 diabetes may be partially mediated by physical activity levels.

One study, published in The Lancet Planetary Health, analyzed the impact of pollution on a group of United States veterans with no previous history of diabetes. The team of scientists followed these participants for a median of 8.5 years, using various models tested against parameters such as ambient air sodium concentrations and lower limb fractures. The results showed a strong link between air pollution and diabetes, suggesting that environmental protection officials must take high-priority steps to minimize air pollution and decrease the incidence of type 2 diabetes.

Older adults

Air pollution is linked to a higher risk of mortality in older adults, particularly regarding respiratory and cardiopulmonary diseases. Studies have found a correlation between air pollution and respiratory mortality, with specific pollutants such as BS, SO2, NO2, CO, and PM2.5 being significant factors. For instance, in France, a study found a 9.2% increase in daily respiratory mortality among older adults for a 10 μg/m3 BS increase. Another study in the Netherlands showed that daily mortality risk due to COPD in individuals aged 65 to 74 was associated with exposure to BS, SO2, NO2, and CO.

Ozone (O3) is another critical pollutant that negatively impacts older adults. A meta-analysis revealed that older individuals had a higher mortality risk associated with an increase in daily 8-hour O3 concentration compared to younger people. Even at low levels, ozone can exacerbate respiratory issues in the elderly. Fine particle pollution, especially PM2.5, is also of concern, as it has been linked to premature death, cardiac problems such as arrhythmias and heart attacks, asthma attacks, and the development of chronic bronchitis.

The susceptibility to the adverse effects of air pollution varies among older adults. Factors such as frailty history, comorbidity, and pre-existing diseases can influence their vulnerability. Additionally, studies suggest that older women may be more vulnerable to the impacts of air pollution than older men. Overall, air pollution poses a significant threat to the health of older adults, and understanding their specific limits and risks when exposed to pollution is essential for developing safety recommendations and guidelines for this vulnerable population.

Children

Outdoor air pollution is unhealthy for everyone, but children are especially vulnerable. Children's airways are small and still developing, and they breathe more rapidly and inhale more air relative to their size than adults. Their lungs are not yet fully developed, and they do not have the same defences as adults to fight off infections. As a result, children have more respiratory infections than adults, which increases their susceptibility to air pollution.

Pregnant women

A 2018 study in London, a city with high levels of air pollution, found that particles inhaled by a pregnant woman can move from the lungs, into the bloodstream, and eventually into the placenta. While the impact of these particles on the fetus is not yet fully understood, research has linked exposure to air pollution during pregnancy to low birth weight, abnormal lung development, higher rates of infant mortality, and increased preterm births. A study in Beijing, a city with some of the world's worst air pollution, found that periods of improved air quality during pregnancy were associated with higher birth weights.

Additionally, air pollution has been linked to an increased risk of autism in children. A Harvard study found that women exposed to high levels of particulate matter pollution during their third trimester were twice as likely to have a child with autism, especially if they lived near a highway. Furthermore, air pollution can exacerbate asthma in pregnant women, leading to preeclampsia, a condition characterized by elevated blood pressure and decreased liver and kidney function. Untreated asthma can also cause oxygen deprivation in the baby, resulting in poor growth, premature birth, and low birth weight.

To reduce the risks associated with air pollution during pregnancy, pregnant women can take several precautions. Checking the Air Quality Index (AQI) can help plan outdoor activities and minimize exposure to polluted air. Investing in air purifiers for the home can also reduce indoor air pollution, creating a healthier environment for the mother and the developing fetus. Pregnant women can also reduce their exposure to household contaminants by using natural cleaners, vent hoods when cooking, and carbon monoxide detectors.

Overall, while air pollution poses health risks to everyone, pregnant women and their unborn children are particularly vulnerable to its harmful effects, underscoring the importance of taking precautions to minimize exposure during this sensitive period.

Frequently asked questions