The article says "average daily peak concentrations of PM2.5 dropped by 3.05 µg/m³. For context, background pollution levels in the region typically hover around 8-9 µg/m³, making this reduction particularly significant for public health."
But 8-9 was already considered a safe level: "Most studies indicate PM2.5 at or below 12 μg/m3 is considered healthy with little to no risk from exposure. If the level goes to or above 35 μg/m3 during a 24-hour period, the air is considered unhealthy." (https://www.indoorairhygiene.org/pm2-5-explained/)
So, good job on reducing pollution, but you already had very safe levels (well, the article doesn't tell us what the old "peak concentrations" were). Since the levels were "little to no risk", the claim of "significant health benefits" (i.e. reduction in disease or death) should be challenged.
Even if the risk was linear/exponential with threshold at 12 for everyone, including infants and elderly, the 30% average reduction is likely mostly done by smoothing the peaks (since you probably have a base level of PM2.5). So you would have more than a 30% reduction in days in which you are exposed to above-threshold PM2.5
Btw, it's a very legitimate remark, please don't down vote the parent. (Sorry about meta commentary I try to avoid)
Smaller doses of a poison are better than less small doses. Using coarse linguistic categories to argue otherwise is an abuse of the purpose of categories as a linguistic tool.
Kinda irrelevant, since 12 isn't really a round number (like 10 would be).
Further, the article is essentially saying that there is far less difference between 11 and 13 than might be assumed by a categorical model that says one level is inside the "safe" level and one is outside of it. But that isn't the issue here - 9 was already quite safe, the risk is very close to zero, so going lower doesn't reduce risk much - because the existing risk can't get much lower.
> Smaller doses of a poison are better than less small doses
Since 1996, the EPA has mandated that unleaded gasoline must be below 0.05 grams of lead per gallon. While the elimination of lead up to this point was a massive benefit to public health, is there any significant health benefit to reducing this further below 0.05? If so, who's claiming that and why haven't the standards changed in 30 years?
But 8-9 was already considered a safe level: "Most studies indicate PM2.5 at or below 12 μg/m3 is considered healthy with little to no risk from exposure. If the level goes to or above 35 μg/m3 during a 24-hour period, the air is considered unhealthy." (https://www.indoorairhygiene.org/pm2-5-explained/)
So, good job on reducing pollution, but you already had very safe levels (well, the article doesn't tell us what the old "peak concentrations" were). Since the levels were "little to no risk", the claim of "significant health benefits" (i.e. reduction in disease or death) should be challenged.