Forest fires and emission of air pollutants, which include fumes
from vehicles running on diesel and slow burning of coal and
charcoal, release isocyanic acid in the troposphere. In 2011,
scientists first detected isocyanic acid in the ambient
atmosphere at levels that are toxic to human populations; at
concentrations exceeding 1 parts-per-billion by volume (ppbv),
human beings could experience tissue decay when exposed to the
toxin. For the first time, using a chemical transport model
designed to estimate the distribution and budget of isocyanic
acid in the troposphere, Young et al. show that in several parts
of the world, local emissions may increase the concentration of
isocyanic acid in ambient atmosphere, thereby exposing large
populations to potentially toxic levels of the acid. Their
research shows that regions that experience large forest fires,
such as tropical Africa, Southeast Asia, Siberia, Canada, and
the Amazon, or are heavily polluted, like China, are
particularly vulnerable. In these regions,