> I couldn’t tell if the study found that car brakes are more harmful than exhausts, or that car brake chemicals are more harmful than exhaust fumes
None of these.
The actual linked study found that the presence of specific metal particulates (copper, zinc and iron), which are found in modern brake dust, correlates with increase risk of asthma and allergy in kids.
I'm personally wondering if the article linked the wrong article? Because the article describes the study as "researchers grew human lung cells in a lab and exposed them to dust from car brakes and from diesel tailpipes", but the linked study is a cohort study of correlation, that doesn't involve any experimental manipulation.
None of these.
The actual linked study found that the presence of specific metal particulates (copper, zinc and iron), which are found in modern brake dust, correlates with increase risk of asthma and allergy in kids.
I'm personally wondering if the article linked the wrong article? Because the article describes the study as "researchers grew human lung cells in a lab and exposed them to dust from car brakes and from diesel tailpipes", but the linked study is a cohort study of correlation, that doesn't involve any experimental manipulation.