Air pollution poses a great environmental risk to health. Outdoor fine particulate matter (particulate matter with an aerodynamic diameter less than 2.5 microns) exposure is the fifth leading risk factor for death in the world, accounting for 4.2 million deaths and over 103 million disability-adjusted life years lost according to the Global Burden of Disease Report. The World Health Organization attributes 3.8 million additional deaths to indoor air pollution.
Air pollution can harm acutely, usually manifested by respiratory or cardiac symptoms, as well as chronically, potentially affecting every organ in the body. It can cause, complicate, or exacerbate many adverse health conditions. Tissue damage may result directly from pollutant toxicity because fine and ultrafine particles can gain access to organs, or indirectly through systemic inflammatory processes. Susceptibility is partly under genetic and epigenetic regulation. Although air pollution affects people of all regions, ages, and social groups, it is likely to cause greater illness in those with heavy exposure and greater susceptibility. Persons are more vulnerable to air pollution if they have other illnesses or less social support. Harmful effects occur on a continuum of dosage and even at levels below air quality standards previously considered to be safe.
Air Pollution Bad for Pregnancy and Unborn Babies
Exposure to air pollution during pregnancy is associated with adverse pregnancy outcomes and reduced fetal growth. A review of over 13,000 pregnancies in Scotland found that exposure to higher levels of PM2.5, PM10, and NO2 were associated with lower infant head size during pregnancy and at birth. Another study across all trimesters of pregnancy reported that the risk of intrauterine growth restriction was increased among women exposed to higher levels of CO, NO2, and PM2.5. A meta-analysis that included nearly 3 million births across 14 centers from nine developed countries found that, after adjusting for socioeconomic status, maternal exposure to particulate air pollution was associated with a higher risk of low birth weight infants.
Air pollution increases the risk of preterm birth and low birth weight independently and additively to other known risk factors, such as lower socioeconomic status, diabetes, hypertension, and smoking.49 Women who are exposed to higher levels of traffic-related air pollution during pregnancy may be at increased risk of preeclampsia, which may be one mechanism explaining the association with preterm birth. Also, increased exposure to O3 and PM2.5 within 5 hours of delivery has been linked to higher risk of premature rupture of membranes, which predisposes women to preterm delivery.
Several studies have found that air pollution is associated with reduced fertility rates and increased risk of miscarriage. A Mongolian study found a dose-dependent relationship between the monthly average SO2, NO2, CO, PM10, and PM2.5 levels during pregnancy and risk of spontaneous abortions. A few studies have shown or suggested that semen or sperm quality is decreased in areas of high pollution.
Poor Impacted More
Exposures to air pollution and other environmental factors and biological susceptibility are the most important factors determining response. People living in Africa, Asia, and the Middle East on average breathe higher levels of pollutants than those in other parts of the world1 and, therefore, sustain a greater health burden.
Sleep efficiency is decreased in most polluted areas, especially with increased exposure to NO2 and PM. Several studies show that air pollution is associated with increased sleep apnea symptoms, possibly because of upper airway inflammation from irritant pollutants and airborne allergens and household biomass smoke.
Air pollution may affect sleep adversely in other ways. Traffic-related air pollution is highest near busy streets, which confounds sleep studies because the environment is more often noisy and illuminated. Pollution may also disturb sleep by exacerbating asthma, COPD, or other respiratory or chronic diseases. In addition, pollutants may lead to an inflammatory reaction in the CNS or directly interfere with neuronal function that may affect sleep.
SOURCES – Chest Journal