Thread by @MelanieBenesh

New Health Advisories for 4 #PFAS announced today and they are VERY low
#PFOA: 4 parts per *quadrillion*
#PFOS: 20 parts per *quadrillion*
#GenX: 10 ppt
#PFBS: 2000 ppt

This is a huge deal

#ForeverChemicals | @ewg | ewg.org/news-insights/…

That means #PFAS are toxic in minuscule amounts. Ppq is a tiny, tiny unit of measurement. WA state explained in 2018, "Lay a penny on the ground and compare it — by area — to the entire state of Washington. That is equal to one part per quadrillion." ecology.wa.gov/Blog/Posts/Mar…

Wikipedia describes it another way:
One part per quadrillion (ppq) denotes one part per 1,000,000,000,000,000 (1015) parts, and a value of 10−15. This is equivalent to about two and a half minutes out of the age of the Earth (4.5 billion years) en.wikipedia.org/wiki/Parts-per…

Note that today's announcement doesn't mean #PFAS will be regulated at these very low levels. Health advisories are non-regulatory and non-enforceable. But they are important benchmarks for regulators, especially in the absence of enforceable standards

Health advisories are also entirely health-based whereas most regulations have to take into consideration other factors, like costs and technological feasibility. Those factors often can result in numbers that are higher than advisory levels

Also worth noting that these are *lifetime* health advisories. That means, EPA is calculating safe levels of exposure based on everyday exposure over the course of your lifetime

We can dramatically reduce those lifetime exposures by setting tough drinking water limits, reducing industrial discharges, eliminating non-essential uses--especially in consumer products--and cleaning up existing pollution. The gov't should take all those steps ASAP