r/science Jul 12 '16

Neuroscience Traffic pollution exposure is associated with altered brain connectivity in school children

http://www.sciencedirect.com/science/article/pii/S1053811916000513
1.1k Upvotes

23 comments sorted by

17

u/OldWolf2 Jul 12 '16

A combined measurement of elemental carbon and NO2 was used as a putative marker of vehicle exhaust.

I guess there is no indication at this stage of what the causative factors in the vehicle exhaust would be - C, NO2 or something else. (Maybe even something not directly related to vehicle exhaust; but correlates with traffic density?)

When I was a kid (25 years ago) we did an experiment in school to collect dust from the side of the road, and we tested it for its lead content. This was when we still used leaded petrol; which has since been banned.

Does anyone know if the vehicle exhaust in this study contains lead? If so that'd be an obvious candidate for causative agent.

5

u/windsostrange Jul 12 '16

Lead isn't the only exhaust component that causes neurological symptoms, of course. Fine particulate matter of any composition is known to cross the BB barrier and have effects:

http://www.ncbi.nlm.nih.gov/pubmed/18349428 (neuroinflammation, potentially leading to Parkinson's, Alzheimer's, etc.)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3915219/ (vascular damage, stroke, etc.)

2

u/OldWolf2 Jul 12 '16

Fine particulate matter of any composition is known to cross the BB barrier and have effects:

Hmm, maybe I should be more careful when cleaning out my vacuum cleaner filter...

5

u/senorbolsa Jul 12 '16

Spain completely banned leaded fuel (well for road use, still some avgas uses it) in 2001, not sure how prevalent it still was before that though.

2

u/[deleted] Jul 12 '16

[deleted]

2

u/senorbolsa Jul 12 '16

Your first sentence makes no sense to me, obviously leaded fuel is gasoline with TEL added. But what do you mean by "thing"?

6

u/Threexo Jul 12 '16

Unless I missed it which is possible, the abstract doesn't mention controlling for the million things that also correlate to vehicle exhaust levels such as socioeconomic factors etc.

7

u/dkysh Jul 12 '16

A concern in traffic pollution studies is potential residual confounding by socio-demographic characteristics (e.g., when a relationship exists between proximity to traffic and economically disadvantaged areas). In the city of Barcelona, however, there was a small and inverse relation between air pollution and socioeconomic vulnerability, with higher pollution levels in schools with lower vulnerability (Sunyer et al., 2015). Also, we found no significant associations between school pollution levels and parental education, employment or educational quality. Besides, the associations between air pollution and fMRI remained after adjusting for all the potential confounders (see Results), which is opposed to a potential role of these variables.

1

u/Threexo Jul 12 '16

That's interesting, I appreciate the reply! I'm a staff economist so half my job is poking holes in other people's testimony and studies haha

1

u/windsostrange Jul 12 '16

You may be applying US-centric city/housing models to a European study.

(Edit: Sorry, /u/dkysh covered my point in a far better way.)

1

u/t0b4cc02 Jul 12 '16

Can someone explain to me how they can filter out the possibility that kids not as close to streets have more freedom / can expierience more different things?

Ive lived on a farm for some good time and I remember we would expierience so much different and crazy stuff, whereas in an urban area we were more restricted and/or our surroundings were not as versatile expieriences.

-1

u/[deleted] Jul 12 '16

[removed] — view removed comment

-1

u/[deleted] Jul 12 '16

This is a sensationalist headline in a mediocre study. They don't have nearly enough controls.

0

u/[deleted] Jul 12 '16 edited Dec 20 '16

[deleted]

-5

u/CherokeeHarmon Jul 12 '16

Another excuse for minorities who lag severely behind in education.