A US state health authority has released new drinking water standards for people exposed to chemicals at the centre of the Williamtown contamination scandal because of concerns about the potential for mothers to pass the contaminants on to infants.
The Minnesota state health department this week released new drinking water advisory levels for the chemicals perfluorooctanoic acid and perfluorooctane sulfonate – or PFOA and PFOS – that are “more protective” than those adopted by the US Environmental Protection Authority and Australian health authorities.
The standards represent what health authorities believe is an acceptable level of the contaminants for consumption in drinking water.
The updated values of 0.035 and 0.027 micrograms per litre for perfluorooctanoic acid and perfluorooctane sulfonate respectively are lower than the landmark combined 0.070 health advisory level issued by the US EPA last year.
In a statement, the health department said it had based the lower levels on a “new state-level analysis” of the “potential for mothers to pass along the chemicals to fetuses and nursing infants”.
“The values apply to short periods of time ie., weeks to months, during pregnancy and breastfeeding, as well as over a lifetime of exposure,” the statement read.
“The revision is based on the understanding that PFOA and PFOS stay in the human body for years and can increase with additional exposures, and can cross the placenta and are secreted in breast milk.”
The decision will again draw attention to Australia’s own standards for the chemicals. Earlier this year the advised exposure level was lowered from 0.5 to 0.07 micrograms per litre for PFOS and from 5 to 0.56 micrograms per litre for PFOA.
That decision came after the government was criticised for adopting standards 78 times higher than what was deemed safe by the US EPA.
In its updated advice the Minnesota health department said that it believed “the immediate health risks for most people exposed to PFCs are low” but that “the latest information from EPA identifies a possible risk for developing fetuses and infants”.
In Minnesota, where PFOA and PFOS manufacturer 3M has its headquarters, the chemicals were discovered in drinking water close to its manufacturing plant in the early 2000s.
It prompted numerous studies into the spread of the contaminants, as well as a state-government legislated bio-monitoring project of populations in two counties east of Minneapolis.
Australian health authorities have acknowledged that the contaminants can be transferred in utero, but have not adopted specific exposure standards for pregnant women.
Earlier this month the Newcastle Herald reported one newborn baby returned levels of PFOS in her blood well above above the national average for children up to four years of age.