Re: Air pollution linked to cognitive decline

[Guest guest]

This is a fascinating study. It essentially says that dirty air makes women

dumber as they get older. No offense

is intended. Not sure why men were not affected (unless we are already dumber

!.

We know that PM 10 and PM 2.5 was significantly higher in the 30s to the 60s

before air pollutions regulations.

I don't remember my grand mother's being less aware at this ripe old age,

because they were both dead. (Due to air pollution?)

So this study had to have been conducted based on TSP data POST air pollution

regulations. 1970s. 80s, etc.

Does this mean that the TSP regulations are not restrictive enough? The

secondary TSP standard is 60 µg/m3.

The study says that " a 10 microgram/m3 increase in long term PM exposure was

cognitively equivalent to aging by approximately 2 years. "

60 µg/m3 is a low outside level. Getting it much lower may not be possible due

to anthropometric sources.

The PM 2.5 standard is 15 µg/m3. so this can't go much lower.

What this is leading me to conclude is that there was a lot more INDOOR TSP and

PM 2.5 exposure.

The lack of evaluation of INDOOR exposures on long term air quality studies has

been one of their criticisms over the years.

This one seems to be especially critical.

Bob

[Guest guest]

Perhaps a better model than the weight/mass of particulates in the air is

considering what will dissolve through the alveoli into the bloodstream when

said pollution is inhaled.

As a peculiarly sensitized individual, it was confusing early on to discover

that the HEPA filters I bought only made a difference for a day or two before

reaching steady state. Likewise discovering that I could make a difference in

my family's health (and cognitive ability) by changing a furnace filter which

was only a few days old under certain circumstances. Concluded that what

science knew how to measure is not aligned with what is affecting my nervous

system.

Two observations on what's changed in the last 40 years:

Wood burning: clean, seasoned wood is maybe 1 or 2% " ash content " . By ash I

mean low molecular weight, water soluble inorganics from the soil. The

approximation that all wood is the organics which in perfect combustion become

water and CO2 neglects this component. Some of the ash lands in the bottom of

the fireplace. Some goes up the chimney. Before pollution controls what went

up the chimney was typically stuck to large particulates which fell out of the

air quickly. With much better combustion, it's dissolved in the water exiting

the chimney (even more so industrially when the particulates are removed by

pollution control equipment). Meaning all of it can reach my lungs. Nanograms

of PM0.1 impact me far more than micrograms of PM 2.5.

Auto exhaust: starting in 1974 the use of catalytic converters changed previous

air pollutants into sulfuric and nitric acids coming out the tailpipes of cars

dissolved in the water resulting from combustion. The subsequent issues around

precipitation with pH significantly below 7, and very brutal special interest

politics in this area during the 1980s, faded without public understanding of

how this issue was resolved. Having been a kid in Los Angeles in the 1960s I

fully appreciate the value of auto pollution controls. However, I remain

surprised that reported NOx pollution measurements to this day include NO and

NO2 but not NO3. I also don't know what was added to that nitric and sulfuric

acid coming out auto tailpipes to get its pH closer to 7, but noted with

interest the paper a few years ago citing an unusual presence of iron in/on some

tree leaves along a busy street.

There are more things which have changed in the last 40 years: widespread use of

petrochemical-solvent fragrances; universal use of pesticides; fabric finishes

in the clothes and bedding one is in contact with 24 hours a day; likewise the

detergents used to clean those clothes and bedding, and the increased amount of

detergent residue left in the clothes as we reduce the water consumption of

washers; the ubiquitous use of anodized metal finishes in commercial buildings

which shed their surface into the ambient air instead of needing labor intensive

cleaning/polishing; repurposing of air conditioning as temperature control only

rather than its initial purpose of humidity control; reduction of ventilation in

both commercial and residential buildings to save energy/money.

Back to the study below: whether it means the outdoor air isn't clean enough to

dilute the indoor air any more, or that the outdoor PM is correlated with but

not the cause of the decline, or more likely something else, we don't know. My

personal experience is that the models science uses today don't account for what

happens to me. My guess is that we won't really understand the causation behind

this study's results until science finds a new generation of models.

Steve Chalmers

stevec@...

>

> This is a fascinating study. It essentially says that dirty air makes women

dumber as they get older. No offense

> is intended. Not sure why men were not affected (unless we are already

dumber !.

>

> We know that PM 10 and PM 2.5 was significantly higher in the 30s to the 60s

before air pollutions regulations.

>

> I don't remember my grand mother's being less aware at this ripe old age,

because they were both dead. (Due to air pollution?)

>

> So this study had to have been conducted based on TSP data POST air pollution

regulations. 1970s. 80s, etc.

>

> Does this mean that the TSP regulations are not restrictive enough? The

secondary TSP standard is 60 µg/m3.

>

> The study says that " a 10 microgram/m3 increase in long term PM exposure was

cognitively equivalent to aging by approximately 2 years. "

>

> 60 µg/m3 is a low outside level. Getting it much lower may not be possible

due to anthropometric sources.

>

> The PM 2.5 standard is 15 µg/m3. so this can't go much lower.

>

> What this is leading me to conclude is that there was a lot more INDOOR TSP

and PM 2.5 exposure.

>

> The lack of evaluation of INDOOR exposures on long term air quality studies

has been one of their criticisms over the years.

> This one seems to be especially critical.

>

> Bob

>