In the US city of Pueblo in the state of Colorado there has been a sharp drop in the number of hospital admissions for heart attacks following the introduction of a law that made it illegal to smoke in public spaces and workplaces. And the drop was steady for three years, said the US Center for Disease Control and Prevention (CDC).
The CDC study, which is reported in this week’s Morbidity and Mortality Weekly Report (MMWR), found there were 399 hospital admissions for heart attack in Pueblo over the 18 months preceding the introduction of the smoke-free ordinance on 1 July 2003. This figure fell by 27 per cent in the 18 months following the ban and then another 19 per cent in the next 18 months (the most recent period for which figures exist).
The agency said that although nine studies have been published showing that banning smoking in indoor workplaces and public spaces is linked to large and rapid falls in heart attack hospitalization rates, none of them looked further than one year beyond implementation of the ban. This latest study covers three years after the date, suggesting that the initial fall expected from the results of other studies is actually sustained over a longer period.
The CDC said it was second hand smoke exposure rather than first hand smoking that has probably made the biggest impact on these figures.
The CDC investigators also examined data on two nearby areas that had not implemented smoke-free bans and found no significant fall in rates of hospital admissions for heart attacks over the same periods.
Among adult non-smokers, long term exposure to second hand smoke has been linked to a 25 to 30 per cent increased risk of heart disease, said the CDC, and about 46,000 nonsmokers die from heart disease every year in the US.
Breathing second hand smoke causes blood platelets to stick to each other, much the same as they do in the blood of smokers, according to research. Even a short time in a smoky room can start this process, said the CDC, who also explained that secondhand smoke can also damage the lining of blood vessels. These two effects: higher coagulation and damage to arteries near the heart, increases the chance that a clot will form, impede blood flow and cause a heart attack.
Director of CDC′s National Center for Chronic Disease Prevention and Health Promotion, Dr Janet Collins, said:
“We know that exposure to secondhand smoke has immediate harmful effects on people′s cardiovascular systems, and that prolonged exposure to it can cause heart disease in nonsmoking adults.”
“This study adds to existing evidence that smoke-free policies can dramatically reduce illness and death from heart disease,” she added.
” Reduced Hospitalizations for Acute Myocardial Infarction After Implementation of a Smoke-Free Ordinance — City of Pueblo, Colorado, 2002-2006.”
US Centers for Disease Control and Prevention (CDC)
MMWR January 2, 2009 / 57(51);1373-1377
Sources: CDC.
Written by: Catharine Paddock, PhD