Researchers with the Forum of International Respiratory Societies Environmental Committee reviewed studies that assessed the impact of air quality interventions on health outcomes and how long it took to achieve these outcomes.
“Within a few weeks, respiratory and irritation symptoms, such as shortness of breath, cough, phlegm, and sore throat, disappear; school absenteeism, clinic visits, hospitalizations, premature births, cardiovascular illness and death, and all-cause mortality decrease significantly,” write lead author Dean E. Schraufnagel, MD, from the University of Illinois at Chicago, and colleagues.
The most immediate improvements were noted following a smoking ban in Ireland in 2004. Within 1 week of the ban, there was a 13% decline in all-cause mortality, a 32% reduction in stroke, a 26% reduction in ischemic heart disease, and a 38% decrease in chronic obstructive pulmonary disease. The greatest improvements were seen among younger individuals and nonsmokers.
Similar improvements were found in western European and Asian countries that have instituted air quality regulations. For example, efforts to curb transportation-related emissions in Hong Kong and Japan have led to declines in all-cause and respiratory mortality as well as a decline in the incidence of pediatric asthma, respectively.
In the United States, data from the Environmental Protection Agency indicate that, since implementation of the Clean Air Act of 1970, approximately 230,000 deaths have been avoided per year due to improvements in air quality. Further benefits include “reductions in premature mortality due to lower ozone concentrations (7100 deaths avoided per year), reductions in acute myocardial infarction (200,000 fewer cases per year), avoided hospital admissions for respiratory conditions (66,000 fewer admissions per year), and reductions in asthma exacerbations (2.4 million fewer attacks per year).”
Factory closures and alternate transportation strategies were also associated with dramatic improvements in respiratory health. Following the 13-month closure of a steel mill in Utah, researchers noted a decline in hospitalizations for pleurisy, bronchitis, and asthma, as well as a decline in school absenteeism. Women who were pregnant during the closure were also less likely to have premature births when compared with women who were pregnant before and after the closure.
During the 1996 Olympic games in Atlanta, Georgia, increased reliance on public transportation and a reduction in private automobile traffic, resulted in a 28% decrease in peak daily ozone concentrations. In the 4 weeks following these changes, there was a 42% decline in children seeking medical care for asthma (based on Medicaid data), a 19% decrease in asthma hospitalizations, and an 11% decrease in pediatric emergency department visits.
Similarly, travel restrictions implemented during the 2008 Beijing Olympics also led to improvements in air quality and improved health outcomes. Within 2 months, there were 58% fewer asthma-related healthcare visits and less cardiovascular mortality reported.
Reductions in indoor air pollution also had significant health benefits. In Mexico, replacement of wood or kerosene stoves with “clean” stoves that use less-polluting fuels led to improved lung function among children 5 to 8 years of age, compared with those in homes with traditional stoves. In countries such as Bolivia and China, the installation of chimneys in homes using coal stoves resulted in a lower incidence of chronic obstructive pulmonary disease and improved respiratory function.
In New Zealand and Australia, use of less-polluting heating sources in homes and schools was also found to improve indoor air quality, leading to a decline in school absenteeism and a reduction in asthma symptoms among children.
“Air pollution is largely an avoidable health risk that affects everyone, although the most vulnerable — the ill, the elderly, children, and the poor — face disproportionate risks,” write Schraufnagel and colleagues.
“The studies presented in this article are examples of actions taken that produced favorable results and can be applied in other settings,” they conclude.
The authors have disclosed no relevant financial relationships.
Ann Am Thorac Soc. 2019;16:1478-1487. Full text