We are back in the haze. Wildfires in Canada are wafting smoke into our area. You see it in the haze, the reddish hues around the sun, especially around sunrise and sunset. And air quality alerts are on the media outlets.
Turns out that elevated levels of these particles carry risks. It’s been known for decades that air pollution (small particulates) raise the risk of lung diseases, heart attacks, even strokes. Now there’s an article that shows that the wildfire smoke doesn’t just raise your risk in the short term, but that risk carries forward for at least 3 months.
If you are one of the “sensitive” groups – lung problems, heart problems – then try to stay inside and keep the windows closed when there’s an air quality alert. It might just save your life.
FROM EPIDEMIOLOGY / BY WEI, YAGUANG; CASTRO, EDGAR; YIN, KANHUA; SHTEIN, ALEXANDRA; VU, BRYAN N.; DANESH YAZDI, MAHDIEH; LI, LONGXIANG; LIU, YUXI; PERALTA, ADJANI A.; SCHWARTZ, JOEL D.
Abstract
Background:
Wildfire activity in the US has increased substantially in recent decades. Smoke PM2.5, a primary wildfire emission, can spike for months after a wildfire begins, yet large-scale evidence of its health effects remains limited.
Methods:
We obtained hospitalization records for the residents of 15 states between 2006–2016 from the State Inpatient Databases. We used existing daily smoke PM2.5 estimations at 10-km2 grid cells across the contiguous US, and aggregated them to ZIP codes to match the spatial resolution of hospitalization records. We extended traditional case–crossover design, a self-controlled design originally developed for studying acute effects, to examine associations between 3-month average exposure to smoke PM2.5 and hospitalization risks for a comprehensive range of cardiovascular (ischemic heart disease, cerebrovascular disease, heart failure, arrhythmia, hypertension, other cardiovascular diseases) and respiratory diseases (acute respiratory infections, pneumonia, COPD, asthma, other respiratory diseases).
Results:
We found that 3-month exposure to smoke PM2.5 was associated or marginally associated with increased hospitalization risks for most cardiorespiratory diseases. Hypertension showed the greatest susceptibility, with the highest hospitalization risk associated with 0.1 µg/m3 increase in 3-month smoke PM2.5 exposure (relative risk: 1.0051; 95% confidence interval: 1.0035, 1.0067). Results for single-month lagged exposures suggested that estimated effects persisted up to 3 months after exposure. Subgroup analyses estimated larger effects in neighborhoods with higher deprivation level or more vegetation, as well as among ever-smokers.
Conclusions:
Our findings provided unique insights into medium-term cardiorespiratory effects of smoke PM2.5, which can persist for months, even after a wildfire has ended.