Brain cancer epidemiology

There are also some human epidemiological studies which show an association between occupational exposure to MC and increases in biliary (bile duct) cancer and a type of brain cancer. Other epidemiological studies have not observed a relationship between MC exposure and cancer. OSHA interprets these results to mean that there is suggestive (but not absolute) evidence that MC is a human carcinogen. 

Two epidemiological studies of workers exposed to ethylene oxide revealed increased rates of leukemia. In one smdy, two cases of leukemia (0.14 expected) and three stomach cancers (0.4 expected) were observed. The other study found three cases of leukemia (0.2 expected). Because these workers had exposures to other potential carcinogens, the findings cannot be linked with certainty to ethylene oxide. The small cohort size, the small number of deaths, and uncertainties about exposure level have also been noted." A number of other studies have not found an increased rate of cancer mortality from ethylene oxide exposure. A mortality study of over 18,000 ethylene oxide workers from 14 plants producing medical supplies and foodstuffs did not find an excess of leukemia or brain, stomach, or pancreatic cancers. There was, however, an increase in non-Hodgkin lymphoma in male workers. A follow-up of 1896 ethylene oxide production workers did not find an increase in mortality from leukemia, non-Hodgkin lymphoma, or brain, pancreatic, or stomach cancers. ... 

Cancer. There is no specific evidence from epidemiological studies that diazinon causes cancer in humans. Several studies have reported an increased incidence of cancers (brain tumors, Hodgkin s lymphoma, multiple myelomas) in humans who were concurrently or sequentially exposed to a number of insecticides, including diazinon (Cantor et al. 1992 Davis et al. 1993 Morris et al. 1986). However, it is not possible to attribute the increase in cancer incidence exclusively to diazinon exposure. Consequently, while the findings in these studies suggest an elevated risk for the cancers from high exposure to insecticides, in general, the data are far too limited to be used to evaluate the potential for diazinon to cause cancer in humans. 

In man, a number of epidemiological studies using different designs have been conducted (17) on the health risks of non-medical exposure to formaldehyde and also in health-care professionals (18-23), with contradictory results. Cancers in excess in more than one study were Hodgkin s disease (24,25), leukemia (18,19,22,23,26), cancers of the buccal cavity and pharynx (particular the nasopharynx) (18,19,25,27,28), lung (18,24,27,29-31), nose (32-36), prostate (19,24,26), bladder (19,23,26), brain (20), colon (18-20,25,27), skin (18,25), and kidney (27). 

Kirman, C. R., Gargas, M. L., Marsh, G. M., Strother, D. E., Klaunig, J. E., Collins, J. J., and Deskin, R. (2005). Cancer dose- -esponse assessment for acrylonitrile based upon rodent brain tumor incidence Use of epidemiologic, mechanistic, and pharmacokinetic support for nonlinearity. Regul Toxicol Pharmacol 43, 85-103. 

Methylene chloride is a common ingredient of paint strippers. On a house, an alternative is to heat with a heat gun, then scrape off the paint with a putty knife. Other solvents are needed for stripping finishes from furniture. Epidemiological work suggests that methylene chloride can cause cancer of the liver, bile duct, and brain.214 It is possible that a professional furniture refinisher could be hired to remove the finish by ultrasonic cleaning or bombardment with particles. Further work is needed. 

The most recent review of the epidemiological evidence merely extends the inconclusive verdict although no firm links have been found between dietary intakes of nitrate and stomach, brain, esophageal, and nasopharyngeal cancers, an association caimot be ruled out. In contrast to these continuing epidemiological uncertainties, the undesirable impacts of water-borne reactive nitrogen on aquatic ecosystems have... 

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