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Health Effects ........... this page under construction ........... Polycyclic Aromatic
Hydrocarbons Sources Working in certain industries such as foundries, coking plants and metal working can expose you to airborne PAH's. Tobacco smoking and living with or close to solid fuel domestic heating can also expose you to dangerous levels of PAH's. Health Effects Many of the airborne PAH's are carcinogenic in the long term with lung cancer being the main outcome. At least 25 000 lung cancer deaths in the UK are caused by inhaled carcinogens, mostly from tobacco smoke but up to 4000 lung cancer deaths are thought to be from other causes. Exposure We are exposed to PAHs by inhaling smoke from coal, wood and tobacco mostly attached to fine particles but some remain as vapour in air. We ingest PAH's by drinking contaminated water and eating food much of which contains tiny amounts of PAH's but certain foods such as smoked, barbecued, flame-grilled or char-grilled meats can contain levels of PAH's which are of very serious concern. Epidemiology has shown that workers chronically exposed to fumes containing combustion products from coke and coal gas manufacture and in aluminium smelters are at an increased risk of lung cancer. Benzo-a-pyrene is used as a marker to indicate the presence of PAH's and the UK government has established a limit of 0.25ng/m3 as an annual average in ambient air to protect the population from cancer due to PAH inhalation. Ambient air (average annual) in a domestic solid fuel heating area is known to vary between 1ng/m3 (Lisburn, NI) and 4ng/m3 (Christchurch, NZ). Rooms with a wood burning stove have been measured to have peaks of several hundred ng/m3 BaP. Wood smoke has been reported to be over ten times the carcinogenic potency as tobacco smoke. A cigarette typically emits 100ng BaP. A 50m3 room with a peak of 400ng/m3 due to a wood stove is the equivalent of having 200 cigatettes smoked in it. |