maneb and Thyroid-Neoplasms

In January 2021, the European Union ended the license of Mancozeb, the bestselling ethylenedithiocarbamate (EBDC) fungicide, because of some properties typical of human carcinogens. This decision contrasts the IARC classification of EBDC fungicides (Group 3, not classifiable as to human carcinogenicity). A systematic review of the scientific literature was conducted to explore the current evidence.. Human and experimental studies of cancer and exposure to EBDC fungicides (Mancozeb, Maneb, Zineb, and others) and ethylene thiourea (ETU), their major metabolite, published in English as of December 2021, were retrieved using PubMed, the list of references of the relevant reports, and grey literature.. The epidemiological evidence of EBDC carcinogenicity is inadequate, with two studies each suggesting an association with melanoma and brain cancer and inconsistent findings for thyroid cancer. Experimental animal studies point at thyroid cancer in rats and liver cancer in mice, while multiple organs were affected following the long-term oral administration of Mancozeb. The mechanism of thyroid carcinogenesis in rats has also been shown to occur in humans. Genotoxic effects have been reported.. The results of this systematic review suggest inadequate evidence for the carcinogenicity of EBDC fungicides from human studies and sufficient evidence from animal studies, with positive results on three out of ten key characteristics of carcinogens applying to humans as well. An IARC re-evaluation of the human carcinogenicity of EBDC fungicides is warranted.

Topics: Animals; Carcinogens; Fungicides, Industrial; Humans; Maneb; Mice; Rats; Thyroid Neoplasms

The fungicide mancozeb has been suspected of causing thyroid cancer and neural tube defects. The aim of the study was to investigate associations of indicators of mancozeb exposure with thyroid cancer and neural tube defects in farmers' families.. National registers in Norway, identifying 105 403 female and 131 243 male farmers, born in 1925-1971, and their 300 805 children available for analyses, born in 1952-1991, were cross-linked with national agricultural censuses, 1969-1989, and the population register. Neural tube defects (ICD-8 740-742) at birth among the 102 703 children conceived between May 1973 and April 1991 were identified in the medical birth register. Likewise thyroid cancer (ICD-7 194) was identified in the cancer register through 2000. Data on farm production and fungal forecasts (humid and temperate weather conditions) in 1973-1990, obtained from agricultural censuses and meteorological measurement stations, respectively, served as the mancozeb exposure indicators. The adjusted rate ratio or prevalence ratio (PR) estimates with 95% confidence intervals (95% CI) were computed in a Poisson regression analysis.. Neural tube defects (131 cases, prevalence 12.8/10 000 births) was moderately associated with potato cultivation (PR 1.6, 95% CI 1.1-2.3) and paternal work of > 500 hours/year (PR 1.6, 95% CI 1.1-2.5). Altogether 319 thyroid cancer cases were identified: 141 in female farmers (incidence 10.2/100 000 person-years), 79 in male farmers (incidence 3.2/100 000 person-years), and 99 in offspring (female and male incidence 3.4 and 0.6/100 000 person-years, respectively). Mancozeb exposure was not associated with thyroid cancer.. A moderate association seems to exist between mancozeb exposure and neural tube defects, but not between mancozeb exposure and thyroid cancer.

Topics: Agriculture; Family; Female; Fungicides, Industrial; Humans; Male; Maneb; Neural Tube Defects; Norway; Occupational Exposure; Prevalence; Registries; Risk Factors; Thyroid Neoplasms; Zineb

Topics: Environment; Epidemiologic Studies; Fungicides, Industrial; Humans; Maneb; Occupational Exposure; Reproducibility of Results; Sister Chromatid Exchange; Thyroid Hormones; Thyroid Neoplasms; Zineb