Mercury toxicity in wildland firefighters

Objective: Recent studies have shown that significant levels of mercury are being released into the atmosphere by wildland fires throughout the United States. Eagle populations in the western United States are experiencing mercury toxicity in areas where many of these massive fires are occurring. We hypothesized that wildland firefighters exposed to smoke and other contaminates from these extensive fires would also reflect elevated blood levels of mercury.

Methods: Wildland firefighters in the western United States were studied during the summers of 2007, 2008, and 2009. Pre- and post-fire season blood samples were tested for mercury in a cohort of firefighters and control subjects.

Results: Over the course of 3 summers, 66 firefighters were studied (41 had pre- and postseason blood draws). In 2008 and 2009 a control group was added with a total of 39 subjects (24 had pre- and postseason blood draws). Detectable blood levels of mercury were found in 6 firefighters, and 1 elevated level was found over the course of the study period. Six control subjects had detectable mercury levels, and no elevated levels were found.

Conclusions: This study did not show statistically significant elevated blood levels of mercury in our cohort of wildland firefighters. However, as forest fires continue to ignite, we recommend continued investigation to ensure the health and safety of firefighting crews.