Ans: A (Asbestos) Ref Harrison 17th/l 613-14: Park 23rd/307, 20th/712]"Mesotheliomas both pleural and peritoneal, are associated with qsbestos" exposure. In contrast to lung cancers, these tumors do not appear to be associated with smoking. Relatively short-term asbestos exposures of <1-2 years or less, occurring up to 40years in the past, have been associated with the development of mesotheliomas"- Harrison 17th/1613"Mesothelioma has been shown to have a strong association with crocidolite varietyof asbestos "-Park 20th/712Table (Harrison): Categories of Occupational Exposure and Associated Respiratory ConditionsOccupationalExposuresNature of Respiratory ResponsesCommentInorganic Dusts Asbestos: mining, processing, construction, ship repairFibrosis (asbes- tosis), pleural disease, cancer, mesothelioma0Virtually all new mining and construction with asbestos done in developing countriesSilica: mining, stone cutting, sandblasting, quarryingFibrosis (silicosis), PMF, cancer, silicotubereulo- sisP; CO PDImproved protection in United States, persistent risk in developing countriesCoal dust: miningFibrosis (coal workers' pneumoconiosisQ, PMF. COPDRisk dropping in United States, increasing where new mines openBeryllium: processing alloys for high- tech industriesAcute pneumonitis, chronic granulomatous diseaseQ, lung cancer (highly suspect)Risk in high-tech industries persistsOther metals: aluminum, chromium, cobalt, nickel, titanium, tungsten carbide, or "hand metal' (contains cobalt)Wide variety of conditions from acute pneumonitis to lung cancer and asthmaNew diseases appear with new process developmentOrganic Dusts Cotton dust: milling, processingByssinosisP (an asthma-like syndromeQ), chronic bronchitis, COPDIncreasing risk in developing countries with drop in United States as jobs shift overseasGrain dust: elevator agents, dock workers, milling, bakersAsthma, chronic bronchitis, COPDRisk shifting more to migrant labor poolOther agricultural dusts: fungal spores, vegetable products, insect fragments, animal dander, bird and rodent feces, endotoxins, microorganisms, pollensHypersensitivity pneumonitis (farmers' lung) Q, asthma, chronic bronchitisImportant in migrant tabor pool but also resulting from in-home exposures