基本上說 偶爾聞聞不會大害 官方資料多為生產工人而發
Q. Fumes from "road tar" or asphalt give me a headache. What is in it? Does it contain carcinogens?
A. Asphalt is the residue of distilling crude petroleum oil, with various admixtures for uses like paving and roofing. Its composition depends on the manufacturing process and the chemistry of the original oilfield. The many hydrocarbons and other molecules it contains vary widely.
“No two asphalts are chemically identical, and chemical analysis defining the precise structure and size of the individual molecules found in asphalt is almost impossible,” according to a study of literature on asphalt fumes by the National Institute for Occupational Safety and Health, part of the Centers for Disease Control and Prevention.
Health guidelines involve manufacturing and installation, not a casual whiff of the fumes on a hot day. Its chief dangers for workers like roofers are listed as eye irritation and respiratory irritation. There may also be headache, nausea, fatigue and drowsiness, but these effects appear to be mild and transient, the guidelines say.
Some asphalts have been found in some laboratory studies to be carcinogenic in animals, but asphalt is described as a potential occupational carcinogen, not a definite risk for humans.
“According to some studies, roofers also have an increased risk of lung cancer,” C.D.C. guidelines say. “But researchers are not sure whether this risk is caused by exposure to asphalt fumes or to other hazards such as smoking, coal tar or asbestos.” Studies continue. The C.D.C. suggests it is common sense to protect against prolonged and excessive exposure to asphalt. C. CLAIBORNE RAY