Lab Matters Fall Winter 2021 - Page 12

ENVIRONMENTAL HEALTH

Climate Change and California Wildfires :

A Look at Environmental Exposures

By Jennifer Liebreich , manager , Environmental Health
Climate change is intensifying the occurrence of extreme weather conditions such as heat waves , drought and lightning storms . In recent years , California has experienced alarming increases in the number of acres burned per year ( Figure 1 ). As of September 2021 , over 2 million acres in the state have already burned this year 1 and that number is growing daily . The most destructive , costly and deadliest fire to date was the 2018 Camp Fire , where approximately 153,000 acres were burned and 18,800 structures were destroyed . 2 With catastrophic events such as wildfires and wildland-urban interface fires , much focus is on the acreage burned and infrastructure damages , but the effects of wildfire smoke on human health are significant and measurable .
In an attempt to examine climate change and its health burden on individuals , toxic chemical exposures experienced by firefighters working the Camp Fire were investigated by the State of California Department of Public Health Environmental Health Laboratory in collaboration with the non-profit Commonweal . Firefighters are frontline responders to wildfires , sentinels of the worst fire-related exposures and deserving of study . Firefighters suffer increased mortality rates from various forms of cancers , chronic obstructive pulmonary disease and other diseases . 3
Two groups of toxic chemicals were
4,000,000 3,500,000 3,000,000 2,500,000 2,000,000 1,500,000 1,000,000 500,000
Figure 1 . Number of acres burned per year in California
2016 2017 2018 2019 2020 2021 ( YTD )
measured in clinical samples of 66 Camp Fire firefighters within four days of active duty : polycyclic aromatic hydrocarbons ( PAHs ) and metals . PAHs are known by-products of incomplete combustion , commonly found in exhaust , wood smoke and fumes from asphalt . 4 Toxic metals can be emitted in the combustion of buildings , vehicles and other materials consumed in the fire . Mercury can be emitted from many sources such as through the burning of mercury-rich vegetation and forest soil ( biomass burning ). 5 PAH metabolites were measured in urine samples using isotope dilution gas chromatography coupled with high resolution mass spectrometry ( GC-HR / MS ). Firefighters ’ metals exposure levels were measured in urine and blood samples using inductively coupled plasma

mass spectrometry ( ICP-MS ).

Results from the Camp Fire firefighters most notably indicated elevated levels of all PAHs measured as well as elevated mercury levels in blood , when compared to levels of these chemicals found in the general US population as reported by the US Centers for Disease Control and Prevention ’ s National Report on Human Exposures to Environmental Chemicals . In the future , scientists at the California Department of Public Health Environmental Health
Laboratory , together with collaborators at Commonweal , hope to determine specific relationships between elevated levels of toxic chemicals in these individuals and their particular job duties , length of exposure , and use of personal protective equipment and types . As the impacts of climate change increasingly damage the planet , biomonitoring programs provide concrete investigations into the ripple effects threatening human health and communities . n
References
1 . State of California . Cal Fire Stats and Events . Available from https :// www . fire . ca . gov / stats-events .
2 . Insurance Information Institute . Facts + Statistics : Wildfires . Available from https :// www . iii . org / fact-statistic / facts-statistics-wildfires
3 . Pinkerton L , Bertke SJ , Yiin J , et al . Mortality in a cohort of US firefighters from San Francisco , Chicago and Philadelphia : an update Occupational and Environmental Medicine 2020 ; 77:84-93 . Available from https :// oem . bmj . com / content / 77 / 2 / 84
4 . Centers for Disease Control and Prevention . Polycyclic Aromatic Hydrocarbons ( PAHs ). November 2009 . Available from https :// www . epa . gov / sites / default / files / 2014-03 / documents / pahs _ factsheet _ cdc _ 2013 . pdf
5 . United States Environmental Protection Agency . Mercury Emissions : The Global Context . Available from https :// www . epa . gov / international-cooperation / mercury-emissions-global-context
A laboratory research scientist analyzing PAH metabolites with a GC-HR / MS . Photo : CDPHE
10 LAB MATTERS Fall / Winter 2021
PublicHealthLabs @ APHL APHL . org