wildfires and other biomass burning

biomass burning

Large scale burning of plant material. Some wildfires are larger than they would be naturally because of actions to prevent them over decades. Wildfires may be started by lightning or volcanic eruption, but more often through human behaviour - arson, camp fires, cigarettes.

controlled biomass burning

clearing land of vegetation, may prevent wildfires

wildfires in California

Wildfires in suburban areas result in burning of houses, cars and other anthropogenic materials. Anthropogenic materials create a wider range of burned products than vegetation alone.

aerosols 

fine solid or liquid particles suspended in the air. Aerosols are mainly organic chemical compounds, plus salts. Organic aerosols vary between fires, but include carcinogenic compounds. If buildings burn, may include toxic metals - lead from roofing. Includes very fine particles (<1 μm). Particle size and chemistry change as organic compounds oxidise, vapours condense, particles adhere to each other.

fresh samples

amorphous carbonaceous particles internally mixed with inorganic salts.

After 4 hours: irregular particles and KCl crystals evolve into coated spheres or collapsed aggregates.

acute effects

Exacerbation of asthma, bronchitis and other respiratory conditions, with higher mortality during and after events.

Depression, metabolic dysfunction, reproductive health effects e.g. placental abruption and gestational thyroid dysfunction found in a study of affected parts of USA.

Eye irritation and corneal abrasion reported in Buenos Aires from wildfire smoke.

chronic effects

Probably minor, due to short period of exposure, but not much research.

Indonesian wildfires

Major wildfires in Indonesia in 1997 - forest clearance for logging and palm oil plantation.

15,600 foetal, infant and child deaths inferred from 2000 census. In utero exposure most lethal. Effects of wildfire smoke compounded by wood burning stove smoke for poorer people.

evaluating acute health effects

Correlating emergency asthma medicine sales against measured atmospheric PM2.5. Similar levels of atmospheric PM2.5 from traffic and other sources do not correlate in this way.

wildfire threat to water supply

Many areas of the world lack water and are at high risk of wildfires. Wildfires can contaminate surface waters and groundwaters that supply water treatment plants.

impacts on water quality and supply

Water catchments may be polluted for several years after wildfires. If used for water supply, increased water treatment will be required, or water may be untreatable. Water supply infrastructure may be damaged or access cut off.