Weak PFOS limits in fish
Great Lakes Consortium for Fish Consumption Advisories
Ug/kg means micrograms per kilogram, or parts per billion. We must multiply these values by 1,000 to arrive at parts per trillion.
The Great Lakes Consortium for Fish Consumption Advisories provides guidelines for eight states that border the Great Lakes, although states are free to develop their own advisories. Michigan, for instance, allows people to consume fish containing up to 300 parts per billion of PFOS monthly.
The consortium figures it’s OK to consume an unlimited amount of fish if they contain less than 10,000 parts per trillion of PFOS. People in Michigan can consume two fish monthly containing an average of 80,000 ppt of PFOS.
A recent study by researchers at Harvard University says fish that travel far from contamination sources may retain dangerous levels of the toxins in their filet. They call out regulators for only concentrating on PFOS while other PFAS compounds also contaminate the fish. They call for increased monitoring and more stringent regulations to protect public health.
The graphic below highlights an issue confronting regulators in states across the country. The state of Maryland enacted a ban on the consumption of largemouth bass from Piscataway Creek while allowing the fish to be consumed in the Potomac River. The source of the contamination is located on Piscataway Creek eight miles from the mouth of the creek. The fish travel throughout the watershed where the ban is not present.