It’s because not all rain/runoff goes to water treatment plants. Streets and parking lots go right back to storm drains and the rivers I believe.
Parking lots alone are a big source of pollution and contamination.
It always annoys me when I see people working on their cars, changing brake pads at a Canadian Tire parking lot. Don’t do that there.
I found that article very confusing to follow and poorly written. The headline and the way the article is presented it makes it sound like these chemical concentrations have rapidly risen in recent years to a level such that "rainwater is now unsafe to drink". But that's not what the article is actually saying. Rather, it's saying the safe consumption levels themselves have been adjusted down. It doesn't talk about the chemical levels in rainwater over the past X years: it just takes a snapshot look at the current levels, compares to the new guidelines, and says "rainwater is now unsafe to drink!!1!"
For the one chemical, PFOA, they say the guideline dropped by 37.5 million times; that's a cherry-picked stat, comparing a 2002 West Virginia state guideline that set a safe level at 150,000 nanograms per litre to a recent EPA guideline that sets a new safe level at 4 picograms per litre. Sure, okay, but how long ago did the chemical concentration exceed 4 pg/L? Has this been an issue for 10 years? 25 years? Did we already exceed 4 pg/L in the 19th century?
The conclusion to the article is that the industries that produce these toxic chemicals need to stop producing them and bear the cost of reducing the levels in the environment, but nowhere does it actually talk about the current production of these chemicals. Are they still in wide use? Has new production of the chemicals already been drastically reduced? I think those are far more pertinent issues that are not even glossed over: they're not mentioned at all.
The Following 14 Users Say Thank You to timun For This Useful Post:
I would assume that all well water and ground water would be compromised as well at this point?
Unless every jurisdiction in the world has facilities to neutralize/combat these chemicals getting through into the taps, wouldnt we all be drinking this stuff right now anyway....... and probably have been for years if not decades?
I would assume that all well water and ground water would be compromised as well at this point?
Unless every jurisdiction in the world has facilities to neutralize/combat these chemicals getting through into the taps, wouldnt we all be drinking this stuff right now anyway....... and probably have been for years if not decades?
Health Canada guidelines are such that 200 ng/L (0.0002 mg/L) of PFOA is acceptable, and the City doesn't even report levels below 10 ng/L. I would wager they don't report values below that because they can't measure concentrations lower than that; certainly not down to the picogram (0.001 ng, or 0.000000001 mg/L)...
I found that article very confusing to follow and poorly written. The headline and the way the article is presented it makes it sound like these chemical concentrations have rapidly risen in recent years to a level such that "rainwater is now unsafe to drink". But that's not what the article is actually saying. Rather, it's saying the safe consumption levels themselves have been adjusted down. It doesn't talk about the chemical levels in rainwater over the past X years: it just takes a snapshot look at the current levels, compares to the new guidelines, and says "rainwater is now unsafe to drink!!1!"
For the one chemical, PFOA, they say the guideline dropped by 37.5 million times; that's a cherry-picked stat, comparing a 2002 West Virginia state guideline that set a safe level at 150,000 nanograms per litre to a recent EPA guideline that sets a new safe level at 4 picograms per litre. Sure, okay, but how long ago did the chemical concentration exceed 4 pg/L? Has this been an issue for 10 years? 25 years? Did we already exceed 4 pg/L in the 19th century?
The conclusion to the article is that the industries that produce these toxic chemicals need to stop producing them and bear the cost of reducing the levels in the environment, but nowhere does it actually talk about the current production of these chemicals. Are they still in wide use? Has new production of the chemicals already been drastically reduced? I think those are far more pertinent issues that are not even glossed over: they're not mentioned at all.
Also, the term "forever" chemical is pretty misleading. Sure, some of these chemicals likely have very long half lives, but it's also a very broad category of compounds and some have very short half lives:
All serum PFAS concentrations declined over time. As expected, the half-lives of long-chain PFAS were longer than those of short-chain compounds, reaching almost 3 years in some cases. For example, the researchers estimated the average half-lives for PFHxS at 2.86 years and L-PFOS (a specific form of perfluorooctane sulfonic acid, C8) at 2.91 years. In comparison, the short-chain PFPeS had an estimated average half-life of 0.63 years, and perfluoroheptane sulfonic acid (PFHpS, C7) concentrations were 1.46 years. The shortest estimated half-lives were for perfluorobutanoic acid (PFBA, C4) at 0.12 years and perfluoroheptanoic acid (PFHpA, C7) at 0.17 years.
So for some of the shorter lived chemicals, you're down to about 1% of the concentration within a year, via natural decay.
Rainwater is not safe to drink anymore due to 'forever chemicals'
