We maken ons druk om asbest, maar rook van houtbranden is heilig dus gezond……….
Fine particulate matter linked to acute coronary events, especially in elderly.
Exposure to fine particulate matter air pollution during wildfires may increase risk for cardiac arrest and other acute heart problems, particularly in the elderly, according to Australian researchers.
The time-stratiﬁed case-crossover study, which looked at cardiovascular and respiratory health effects of wildfire smoke (PM2.5; aerodynamic diameter <2.5 lm) from the 2006-2007 bushfires in Victoria, Australia, showed a 6.98% increase in cardiac arrest when ambient air is contaminated by smoke from wildfires, reported Anjali Haikerwal, MBBS, MPH, of Monash University in Melbourne, and colleagues.
Associations were observed for out-of-hospital cardiac arrests, hospital admissions, and emergency department (ED) visits for ischemic heart disease (IHD) after two days of exposure to wildﬁre smoke in Victoria at PM2.5 concentrations, they wrote in the Journal of the American Heart Association.
This association was observed mainly in adults 65 or older. Men showed a higher risk of out-of-hospital cardiac arrests events and women showing a higher risk of IHD-related hospital admissions, they added.
“The results from our study suggest that PM2.5 exposure from wildﬁre smoke may be an important determinant of out-of-hospital cardiac arrest and IHD (ED visits and hospital admissions) and that susceptible persons such as older adults may be at higher risk during such extreme events,” Haikerwal’s group wrote.
One of the most important sources of PM2.5 air pollution is from wildﬁre smoke exposure, the authors pointed out, adding that “smoke from wildﬁres disperses widelyand affects large portions of the population away from the ﬁre source.”
Protracted droughts make Victoria one of the most ﬁre-prone regions in the world. The 2006-2007 wildﬁre was the longest running collection of ﬁres that burned over more than 1 million hectares (about 4,000 square miles) of land in Victoria and lasted for more than 60 days.
Previously, she noted, epidemiological studies investigating the role of fine particulate matter in triggering acute coronary events, including out-of-hospital cardiac arrests and IHD, during wildﬁres, have been inconclusive.
This examination of the associations between of out-of-hospital cardiac arrests, IHD, acute myocardial infarction, and angina (hospital admissions and ED attendance) with PM2.5 concentrations during the 2006–2007 wildﬁres paints a different picture.
“Their data support previous findings of increased cardiovascular hospital admissions during increased air pollution exposure, and basic studies showing that particulate contamination can alter autonomic activity and negatively affect cardiovascular health,” said Alfred Bove, MD, PhD, a cardiologist at Temple University in Philadelphia, in an interview.
“The findings indicate that patients should be made aware of an increased risk for cardiovascular events during times when air pollution is particularly severe, whether from wildfires, heavy vehicle traffic or other exposures,” he told MedPage Today.
He pointed out that it was likely that many of the subjects who experienced a cardiovascular event had underlying cardiovascular disease. For this reason, “patients with known cardiovascular disease should be instructed to avoid air pollution exposures, and find filtered air environments when pollution levels are high, as in the event of environmental smoke contamination from wildfires,” he said.
Bove added that similar advice is appropriate for those without a history of cardiovascular disease.
The authors acknowledged that a study limitation was the the lack of information on personal risk factors such as socioeconomic status, smoking, obesity, and underlying health conditions. They also lacked data on indoor PM concentrations while the wildfires were raging.
During the December 2006 to January 2007 study period, health data were obtained from comprehensive health-based administrative registries. Modeled and validated air exposure data from wildﬁre smoke emissions (daily average PM2.5, temperature, relative humidity) were also estimated for this period.
There were 457 out-of-hospital cardiac arrests, 2,106 ED visits, and 3,274 hospital admissions for IHD, the authors reported.
After adjusting for temperature and relative humidity, an increase in interquartile range of 9.04 lg/m3 in PM2.5 over two days moving average (lag 0-1) was associated with a 6.98% (95% CI 1.03%-13.29%) increase in risk of out-of-hospital cardiac arrests, with strong association shown by men (9.05%,95%CI 1.63%-17.02%) and by seniors (7.25%, 95% CI 0.24%-14.75%).
Increase in risk was 2.07% (95% CI 0.09%-4.09%) for IHD-related emergency department attendance and 1.86% (95% CI 0.35%-3.4%) for IHD-related hospital admissions at lag two days, with strong associations shown by women (3.21%, 95% CI 0.81%-5.67%) and by older adults (2.41%, 95% CI 0.82%-5.67%).
PM2.5 levels during wildﬁre episodes can exceed air quality guidelines set by regulatory bodies such as the World Health Organization, the authors stated, adding that it has long been hypothesized that PM2.5 is particularly toxic because it can penetrate deep into the lungs and induce systemic and oxidative stress responses.
This in turn could potentially trigger a cascade of pathophysiological events and lead to manifestations of CHD, including chronic and angina, plaque instability, and rupture, typically following myocardial infarction and cardiac arrest, they said.
“Given the increased incidence and frequency of wildﬁres recently and the increased number of people at risk of smoke exposure, future research is required to investigate the role of fine particulate matter exposure from wildﬁre smoke in triggering acute coronary events,” they concluded. “The knowledge and evidence resulting from such research will inform policy and practice and help build capacity in the understanding and management of adverse cardiovascular health impacts in vulnerable communities during wildﬁre episodes.”
From the American Heart Association:
The research was funded by Bushﬁre Cooperative Research Centre (Bushﬁre CRC) now a part of Bushﬁre & Natural Hazards Cooperative Research Centre, Melbourne, Victoria, Australia.
Haikerwal and co-authors disclosed no relevant relationships with industry.
- Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner
LAST UPDATED 07.17.2015