Mercury poisoning in Peru's Amazon threatens health disaster

• Illegal gold mines pollute Peru's Loreto region
• Nearly 80% of people have mercury unsafe levels
• Pregnant women and children most at risk

LIMA, Peru - Indigenous and riverine communities in the Loreto region of the Peruvian Amazon have "chronic exposure" to mercury, according to a new study by the Center for Amazonian Scientific Innovation at Wake Forest University in the United States.

The test results released this month show nearly 80% of the people tested late last year had levels of mercury far above the safe limits in six communities on the banks of the Nanay and Pintuyacu rivers, from where Context reported in October last year.

"The majority of the population is contaminated," said Jairo Reategui Davila, the Apu, or leader, of San Antonio de Nanay, one of the tested communities.

"We call on the authorities to take action on the matter because we are very concerned," he said.

The results showed 37% of the 273 men, women and children tested had levels of mercury at more than 10 ppm (parts per million) in their hair, compared to just 3% under the 2.2 ppm 'safe' limit established by the World Health Organization (WHO). 

Gold prices have soared by nearly 50% in the last year, beating successive record highs, and encouraging a flourishing illegal gold mining trade that is damaging local nature and biodiversity, and raising significant health concerns. 

Illegal miners use mercury to extract gold particles from the river silt and then burn off the toxic metal, which turns to vapour and is absorbed by surrounding plants, soil and rivers, said Claudia Vega, head of the mercury programme at CINCIA. 

Mercury poisoning is associated with several health issues, including cognitive impairment in adults and irreversible developmental delays and learning difficulties for children and babies in the womb.

Gabriel Barría, regional coordinator for heavy metals for the local health authority, said it was "very regrettable that villagers were highly contaminated" and blamed the spread of illegal gold mining for the mercury levels in Amazon rivers.

He said the health authority did not have the budget to carry out tests for mercury and had only tested 12 villagers on a recent health visit relying on blood and urine samples. 

Exceeding the limit

CINCIA said tests revealed an average level was 8.41 ppm, exceeding the WHO limit by nearly four times.

Given that illegal mining in Loreto is fairly recent, there are no comprehensive studies on its health impact on the local population yet.

But the levels in these initial tests are already higher than those in the Peruvian Amazon region most impacted by illegal gold mining, Madre de Dios, where 2012 tests showed the majority of adults had average mercury levels of 2.7ppm.

Luis Fernandez, executive director of CINCIA and Research Professor at Wake Forest University, said if illegal mining continued to spread in Loreto, then villagers with already high mercury levels might begin to approach those close to the worst recorded case of mercury contamination.

This includes Minamata Bay, the renowned case in Japan in the 1950s, where children were born with congenital deformities and neurological disabilities caused by a chemical factory dumping mercury into the water supply for decades.

Vega from CINCIA, who led the study, said the results showed worrying "background" levels of mercury in the Loreto riparian communities.

She said it could not be fully determined if the mercury came from naturally occurring sources or human-caused activities like illegal gold mining, but it was mostly caused by the villagers' diet fish-based diet. 

However, "several studies agree that the entry of mining into a territory tends to significantly increase mercury levels in the environment", she said. 

The newly released study found that people were mainly exposed to methylmercury, a highly toxic form that accumulates in the body. 

"[The] greatest risk is for pregnant women and children: methylmercury can cross the placenta and affect the development of the developing baby's brain," she said. "This type of exposure is a serious public health concern, even if affected individuals do not show immediate symptoms." 

(Reporting by Dan Collyns; Editing by Jon Hemming.)