Hidden harm of smoke.
Microbial long-haul flights.
Lurking, infecting.
Wildfires cause huge amounts of long-term harm, including human, other animal and plant deaths, habitat loss, property and infrastructure destruction, the loss of carbon reservoirs and increased chances of flooding and landslides. Small airborne particles in smoke can be inhaled and cause fatal problems within the respiratory system, whilst the high levels of carbon monoxide produced can result in long-term brain damage, heart problems and even suffocation.
Yet researchers are revealing a new potential health threat as a result of wildfires – some microbes and fungi known to cause human infections are able to survive in the smoke plumes. Wildfires disturb soils causing these microbes to become airborne. Within the smoke the microbes ‘travel’ on particulate matter which is likely to protect them from ultraviolet radiation.
Kobziar & Thompson (2020) argue that the ability of microbes to survive in smoke plumes means that wildfires could play a role in geographical patterns of infection and that more research is needed to understand this threat. Particulate matter from wildfire smoke has been found to travel inter-continental distances. Those living close to wildfires, and even more so those firefighters working on the front lines are likely to be most at risk to such microbes – the US Centre for Disease Control has already stated that firefighting is an at-risk profession for coccidioidomycosis, a fungal infection also known as Valley fever.
The researchers argue that too little is currently known about microbe survival and spread in wildfire smoke. Essential questions remain, the answers to which will only be more important as the likelihood of wildfires increases as a result of climate change.
Original research: Kobziar & Thompson, 2020, Science, ‘Wildfire smoke, a potential infectious agent’ https://science.sciencemag.org/cgi/doi/10.1126/science.abe8116