MercoPress. South Atlantic News Agency

Brazil: Mercury detected in Yanomami people's hair samples

Illegal mining has been linked to health issues among the Yanomami population

The Rio de Janeiro-based Oswaldo Cruz Foundation (Fiocruz) conducted a series of tests among Yanomami indigenous people in the state of Roraima in northern Brazil which detected the presence of mercury in 84% of the hair samples taken from them in October 2022, Agencia Brasil reported this week. These findings were linked to illegal gold mining in the area.

“There are metals such as zinc, iron, and selenium that are important for the body as they are involved in human metabolism. For example, iron is crucial for the formation of hemoglobin. However, mercury plays no role in human metabolism, making it a chemical contaminant. Since the 1950s, science has been accumulating evidence of its harmful effects on health,” Fiocruz researcher Paulo Basta said.

The “Impact of Mercury on Protected Areas and Forest Peoples in the Amazon: An Integrated Health-Environment Approach” study was supported by the non-governmental organization Instituto Socioambiental (ISA) and involved collaboration from two Fiocruz departments: the Sergio Arouca National School of Public Health and the Joaquim Venâncio Polytechnic School of Health. The villages included in the study are situated in the Upper Mucajaí River region and are home to Yanomamis from the Ninam subgroup.

A total of 287 hair samples were tested from individuals of various ages, including children and the elderly. Of these, 84% had mercury levels greater than 2.0 micrograms per gram of hair (µg/g). For this age group, it is mandatory to report cases to the Notifiable Diseases Information System (SINAN). This system produces official statistics that guide the actions to be taken within Brazil's public health network, the SUS.

In 10.8% of the analyses, the levels exceeded 6.0 µg/g, which underscores the need for special attention to this segment of the population. The highest exposure levels were observed in indigenous individuals residing in the villages nearest to the illegal mining sites, Agencia Brasil also pointed out.

The Yanomami indigenous land spans over 9 million hectares, stretching across the states of Roraima and Amazonas and standing as the largest indigenous reserve in Brazil. According to the 2022 Census data released by the Brazilian government´s statistic agency IBGE, this area is home to over 27,000 indigenous individuals.

Illegal mining has plagued this territory for decades. Mercury is employed to extract gold from sediments. Given its clandestine nature, environmental precautions are often ignored. This leads to the dumping of mercury into rivers and its subsequent entry into the food chain of fish and other animals. This contamination, coupled with the expansion of illegal mining, has contributed to health issues among the Yanomami population, including malnutrition and an increase in diseases, especially malaria.

(Source: Agencia Brasil)