While it is considered this generally occurs only in an occupational setting following a single acute exposure, chronic exposure to chemicals can cause the same spectrum of effects as a single acute exposure. Asthma can be caused by the same pollutants and the prevalence of this is also growing in the population. This is not surprising as asthma is hypersensitive airways. Many asthma attacks are provoked by allergic reactions and chemical hypersensitivities. Official figures for the percentage of Australian people in the population suffering with chemical sensitivities are unknown.
Any official figures are extremely conservative as they only relate to hospital discharges.
It is already well known that on days of high pollution levels morbidity and mortality are increased. Six criteria pollutants were identified that would require monitoring and reporting protocols. While this NEPM is very welcome, these six criteria pollutants may not necessarily be the substances in the environment that are causing the most health problems. The NEPM does not include hydrocarbons, or toxic substances such as those found around chimneys and incinerators which can contain carcinogenic dioxins, furans, TDI and many other harmful substances. In the USA, the Clean Air Act requires standards that protect public health and safety with an adequate margin of safety.