The study, published in the journal Annals of the American Thoracic Society, reviewed interventions that have reduced air pollution at its source. It looked for outcomes and time to achieve those outcomes in several settings, finding that the improvements in health were striking.
Starting at week one of a ban on smoking in Ireland, for example, there was a 13 per cent drop in all-cause mortality, a 26 per cent reduction in ischemic heart disease, a 32 per cent reduction in stroke, and a 38 per cent reduction in chronic obstructive pulmonary disease (COPD). Interestingly, the greatest benefits in that case occurred among non-smokers.
"We knew there were benefits from pollution control, but the magnitude and relatively short time duration to accomplish them were impressive," said lead author Dean Schraufnagel from the American Thoracic Society in the US.
"Our findings indicate almost immediate and substantial effects on health outcomes followed reduced exposure to air pollution. It's critical that governments adopt and enforce WHO guidelines for air pollution immediately," Schraufnagel added.
According to the researchers, In the US a 13-month closure of a steel mill in Utah resulted in reducing hospitalisations for pneumonia, pleurisy, bronchitis and asthma by half.
School absenteeism decreased by 40 per cent, and daily mortality fell by 16 per cent for every 100 µg/m3 PM10 (a pollutant) decrease.
Women who were pregnant during the mill closing were less likely to have premature births.
A 17-day 'transportation strategy,' in Atlanta, Georgia during the 1996 Olympic Games involved closing parts of the city to help athletes make it to their events on time, but also greatly decreased air pollution.
In the following four weeks, children's visits for asthma to clinics dropped by more than 40 per cent and trips to emergency departments by 11 per cent. Hospitalizations for asthma decreased by 19 per cent.
Similarly, when China imposed factory and travel restrictions for the Beijing Olympics, lung function improved within two months, with fewer asthma-related physician visits and less cardiovascular mortality.
"Fortunately, reducing air pollution can result in prompt and substantial health gains. Sweeping policies affecting a whole country can reduce all-cause mortality within weeks," Schraufnagel said.
Local programmes, such as reducing traffic, have also promptly improved many health measures, said the study.
( With inputs from IANS )