Pacific Northwest wildfires alter air pollution patterns across North America

A new research shows that large and intense wildfires in the Pacific Northwest are changing the seasonal pattern of air pollution and causing a spike in pollutants in August. According to the study, the smoke is posing a risk to the health of millions of people.

Scientists at the National Center for Atmospheric Research found that levels of carbon monoxide, a gas that indicates the presence of other air pollutants, have increased as wildfires spread in August. Carbon monoxide levels are usually lower in the summer because of chemical reactions in the atmosphere related to changes in sunlight, and the finding that their levels have jumped indicates the extent of the smoke's impacts.

The lead author said that the annual pattern of air quality in North America is changing because of the increased fire emissions.

On hot summer days, the presence of more harmful pollutants, including aerosols and ground-level ozone, are more likely to form.

Satellite-based observations of atmospheric chemistry and global inventories of fires were used by the research team to track wildfire emissions over the past two decades. The Pacific Northwest, the central United States, and the Northeast are all in North America.

Carbon monoxide levels have been decreasing globally and across North America due to improvements in pollution-control technologies.

Air pollution impacts are increasing.

Climate change, increased development, and land use policies have led to an increase in the number of wildfires in the Pacific Northwest. The fires are becoming a bigger factor in air pollution as emissions from human activities are decreasing because of more efficient combustion processes in motor vehicles and industrial facilities.

The data from the NASA Terra satellite was used to analyze the impacts of fires. Four inventories of wildfire emissions rely on data from theMODIS.

The beginning of a consistent and long-term record of MOPPIT data was the focus of the scientists.

The peak burning season of the Pacific Northwest coincides with an increase in carbon monoxide levels across North America. The Pacific Northwest fire season became much more active in the last five years. Aerosols showed an upward trend in August.

Scientists eliminated other potential emission sources to determine if the pollution levels were caused by the fires. They found that carbon monoxide levels upwind of the Pacific Northwest were much lower in August, a sign that the pollution was not blowing in from Asia. The fire season in the central U.S. and the Northeast did not coincide with the increase in pollution, which meant that local fires were not to blame. Carbon monoxide emissions from human activities did not increase in any of the three study regions from 2012 to 2018, according to a pair of fossil fuel emission inventories.

Multiple lines of evidence point to the worsening wildfires in the Pacific Northwest as the cause of degraded air quality.

There are risks to human health.

There are implications for human health from the findings because wildfire smoke has been linked to respiratory problems and may affect the cardiovascular system.

The Community Atmosphere Model with a chemistry component was used to model emissions from the Pacific Northwest fires and their impact on carbon monoxide, ozone, and fine particulate matter. The simulations were done at the NCAR-Wyoming Supercomputing Center. The pollutants could affect more than 130 million people, including 34 million in the Pacific Northwest, 23 million in the Central U.S., and 72 million in the Northeast.

The authors looked at respiratory death rates in Colorado for the month of August from 2002 to 2011 and compared them to the same month in 2012 and 2018). Respiratory death rates in Colorado were easy to find in the central U.S. region of the study.

They found that Colorado respiratory deaths increased in August when fires in the Pacific Northwest produced more emissions.

It is clear that more research is needed into the health implications of all this smoke.

More information: New seasonal pattern of pollution emerges from changing North American wildfires, Nature Communications (2022). DOI: 10.1038/s41467-022-29623-8 Journal information: Nature Communications Citation: Pacific Northwest wildfires alter air pollution patterns across North America (2022, April 19) retrieved 19 April 2022 from https://phys.org/news/2022-04-pacific-northwest-wildfires-air-pollution.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.