Data showed that workers exposed to various biocides -- such as sanitizers, disinfectants, and deodorizers -- had a 65 percent increased risk of thyroid cancer. Data also showed that women who were exposed to any form of biocides on the job had a 48 percent likelihood of developing thyroid cancer. Men who had occupational exposure to the chemicals were up to three times as likely to develop thyroid cancer, the researchers added.
“Limited studies have investigated occupational exposure to pesticides in relation to thyroid cancer and have reached inconsistent results. Our study did not support an association between occupational exposure to pesticides and risk of thyroid cancer, but suggested that occupational exposure to other biocides might be associated with an increased risk of thyroid cancer," said lead study author Dr. Yawei Zhang in an article in Reuters.
The researchers did not identify the mechanism behind the link between occupational biocide exposure and increased risk of thyroid cancer. However, they inferred that the chemicals may possibly alter thyroid hormones. Triclosan, for example, was shown to reduce the levels of two thyroid hormones crucial in metabolism and growth. The liver cancer-causing chemical is commonly found in cleaning products. The results recommend that workers “should take caution when they apply pesticides or other biocides in work place or at home by wearing protective clothes or mask and washing hands afterwards,” Dr. Zhang added.
The findings were published in the journal Occupational and Environmental Medicine.
A 2014 meta-analysis found a suggestive correlation between chemical, radiation exposure in workers and increased thyroid cancer risk. Data also showed that cancer risk was observed in pesticide-exposed workers and agricultural occupations. However, researchers said the findings were suggestive, but inconsistent. The researchers also noted that more studies with larger numbers of cases were needed to support the findings. The results were published in the journal Occupational and Environmental Medicine.
Another study published in the International Archives of Occupational and Environmental Health established a link between workplace chemicals and thyroid cancer. Researchers pooled data from Sweden's National Cancer and Death Registries and found that women workers exposed to solvents -- including shoe-cutters, lasters, and sewers -- had an increased likelihood of developing thyroid cancer. The findings demonstrate that solvent exposure in the shoe and leather industries raise the odds of cancer in women workers, researchers said.
The fungicide penconazole, mostly used in grape cultivation, was also linked to higher thyroid cancer risk. Researchers said cultured human cell lines exposed to the endocrine-disrupting fungicide was shown to alter a gene expression that was associated with the onset of thyroid cancer. The findings were published in the journal Toxicology in Vitro.
Pesticide use was also tied to the onset of many other forms of cancer. A report by the Pesticide Action Network North America revealed that farmers and pesticide applicators were at an increased risk of prostate cancer, while women exposed to pesticides has higher odds of developing ovarian cancer.