Chemicals and Cancer in Humans: First Evidence in Experimental Animals

Overview of preventable industrial causes of occupational cancer.

“…Studies have reported elevated rates for urinary tract (29)(30)(31), bladder (32,33), esophageal (29,33), pancreatic (32,34), colon (33), and lymphatic (29) (36,37). Some may question the use of animal studies in identifying potential human carcinogens (38), but a recent review article demonstrated that 25 to 30% of agents, substances, or chemicals that have been causally or strongly associated with cancer in humans were first identified as being carcinogenic in experimental animals (39). Moreover, it is hoped that increased understanding of the molecular mechanisms of cancer induction will allow the design of even more predictive animal models in the future (39).…”

Sawmill Chemicals and Carcinogenesis

“…Clearly, several dioxin-induced tumor sites are common in both humans and in animals. TCDD is another instance where the carcinogenesis findings were first identified in animals and only later in humans (15).…”

“…After all, we know that experimental carcinogenicity data are the prime indicators of potential carcinogenic hazards to humans (7)(8)(9)(10)(11). We also recognize that for all human carcinogens that have been tested in animals, there is a perfect correlation (2,8,(12)(13)(14), and, significantly, for nearly one-third of the known human carcinogens, positive carcinogenesis findings in animals were first identified in experimental animals and only subsequently observed in humans (15,16). This alone surely represents a failure of the public health system, and one hopes that this will happen not at all or less so in the future.…”

A Daubert Motion: A Legal Strategy to Exclude Essential Scientific Evidence in Toxic Tort Litigation

“…Although most rodent carcinogens have not been adequately evaluated in human studies, too often carcinogenic effects that were detected in animal studies were later confirmed in human studies. 20 In some instances, such as that of diethylstilbestrol, animal warnings were ignored and, as a result, many people suffered the consequences of exposure to an agent that causes genital and reproductive abnormalities and cancer in humans. For 1,3-butadiene, the permissible occupational exposure limit promulgated by the Occupational Safety and Health Administration was lowered from 1000 ppm to 1 ppm, 21 but not until more than 10 years after this chemical was shown to be a potent, multipleorgan carcinogen in laboratory animals at exposures considerably lower than the Occupational Safety and Health Administration standard.…”