Dr. Michael Jerrett ISA Summary Chapter – The document is much improved and more tractable. I had no major concerns, except with the characterization that most studies have not dealt with co-pollutants and this is only partly correct. Many studies have dealt with one or two co-pollutants, but not all; so this should be softened to dealt adequately. haven’t On types of evidence, there needs to be some mention of the scripted exposures such as the McCreanor et al. (2007) study. This is a hybrid between controlled exposures and epidemiology and could inform the determinations as well because the exposures are often more realistic than in chambers because they are in real world conditions. Noise should be mentioned more prominently as a potential confounder. The idea that we understand that well should be revised; there are don’t “double jeopardy” specific studies on stress for example Shankardass et al. (2009) that do elucidate this area. On exposures, could you delineate truck vs vehicle dominated roadways this has important – implications for understanding the impact of control measures given the high direct emissions of diesel? There needs to be some caution in comparing to England because there is a larger proportion of diesel vehicles and therefore more primary NO2. I why EPA compare to the wasn’t sure didn’t Canadian data. Health Canada has prepared all of this because they too are revising the NO2 guidelines. Check with Barry Jessiman, Health Canada. The discussion of roadway gradients could be refined by including mention of the types of roadways and volumes of traffic. In general much of the document talks about distance to roadways as though all roads are the same, whether they have 40,000 or 400,000 vpd. This needs to be addressed directly because it could explain why some cities observe higher NO2 levels away from roadways. Conceptual Model still Incomplete physical activity into account doesn’t take fuzzy on what was meant at an indoor environment in vehicle how do we deal with – – that not clear from the current presentation. – The entire document is silent on intake fraction this is a problem because so much of – the NO2 exposure probably occurs close to or at the source so the intake will likely be much greater
Dr. Michael Jerrett ISA – Summary Chapter The document is much improved and more tractable. I had no major concerns, except with the characterization that most studies have not dealt with co-pollutants and this is only partly correct. Many studies have dealt with one or two co-pollutants, but not all; so this should be softened to haven’t dealt adequately. On types of evidence, there needs to be some mention of the scripted exposures such as the McCreanor et al. (2007) study. This is a hybrid between controlled exposures and epidemiology and could inform the determinations as well because the exposures are often more realistic than in chambers because they are in real world conditions. Noise should be mentioned more prominently as a potential confounder. The idea that we don’t understand “double jeopardy” that well should be revised; there are specific studies on stress for example Shankardass et al. (2009) that do elucidate this area. On exposures, could you delineate truck vs vehicle dominated roadways – this has important implications for understanding the impact of control measures given the high direct emissions of diesel? There needs to be some caution in comparing to England because there is a larger proportion of diesel vehicles and therefore more primary NO2. I wasn’t sure why EPA didn’t compare to the Canadian data. Health Canada has prepared all of this because they too are revising the NO2 guidelines. Check with Barry Jessiman, Health Canada. The discussion of roadway gradients could be refined by including mention of the types of roadways and volumes of traffic. In general much of the document talks about distance to roadways as though all roads are the same, whether they have 40,000 or 400,000 vpd. This needs to be addressed directly because it could explain why some cities observe higher NO2 levels away from roadways. Conceptual Model still Incomplete doesn’t take physical activity into account fuzzy on what was meant at an indoor environment – in vehicle – how do we deal with that – not clear from the current presentation. The entire document is silent on intake fraction – this is a problem because so much of the NO2 exposure probably occurs close to or at the source so the intake will likely be much greater
EPA-CASAC-15-001%20unsigned.docx