Quem está mais exposto à poluição no caminho para a escola?

Resultado: ganha a bicicleta.

Mais um estudo que compara o caminhar, o pedalar e o ir de carro para a escola, para ver quem está mais exposto à poluição de partículas PM2.5 (as que penetram nos pulmões e na corrente sanguínea).

No carro é onde estão mais acima dos limites (44%), seguido do caminhar (40%) e do pedalar (28%).
Não só é na bicicleta onde estamos menos expostos à poluição, como são os carros os principais causadores da poluição destas partículas PM2.5.
E no entanto é ver as portas das escolas apinhadas de carros a poluir os pulmões dos filhos pelos próprios pais (para não falar no perigo físico que representam).

Os “selvagens” do século XX e XXI são bem piores e mais mortíferos que os dos livros de história.

5 Curtiram

acho estranho esse resultado… é que honestamente, sinto muito mais fumo quando ando de bike quando ando de carro ou a pe… bike e o unico que levamos com escapes diretamente na cara

2 Curtiram

há muitos estudos que indicam que o ciclista é o menos exposto… outra coisa bem diferente, é dizer que é que menos inala.
se eu tiver exposto a 20% menos de PM, mas respirar o dobro, acabo por inalar mais

2 Curtiram

Table 4 summarizes the 12 published modal comparisons that include respiration, showing the median and range for ratios of bicycle to alternative mode intake or uptake doses. Dose ratios are presented separately for the eight studies that compare doses per unit distance and the five studies that compare doses per unit time (one assesses both). For most pollutants, studies that compare doses per unit distance find greater bicycle/car dose ratios than comparisons per unit time, as expected from bicyclists’ lower travel speeds. This body of literature is still much smaller than modal comparisons of exposure, but for the most part two to five times higher ventilation rates and slower travel speeds for bicyclists compared to motor vehicle passengers outweigh any beneficial exposure concentration differences. Bicyclists’ doses are less consistent when compared to pedestrians, which is not surprising because walking is another active travel mode with elevated respiration. Pedestrians typically have lower respiration rates (McNabola et al., [2007]) but also lower speeds, with counteracting effects on intake rates per unit distance.

[…]

This is the first review to specifically address bicyclists’ health risks from traffic-related air pollution and to explicitly include intake and uptake doses in addition to exposure concentrations. Bicyclists’ pollution exposure concentrations are highly variable, with median increases of up to 102% (for gaseous hydrocarbons) on high-traffic versus low-traffic routes. Bicyclists’ relative exposure concentrations compared to other modes are inconsistent, varying by pollutant, facility, route, and city. Bicyclists’ exposure concentrations are most affected by wind and proximity to motor vehicle traffic, though few studies have incorporated detailed, concurrent traffic data.

Bicyclists’ pollution intake doses tend to be higher than motorized modes due to their two to five times higher respiration rates. Bicyclists’ respiration and intake dose increase with bicycle travel speed and exertion, but only 12 of the 57 studies with spatially explicit bicyclist exposure concentration data include any measurement of respiration. Furthermore, only three of those studies consider variable bicyclist respiration rates, and there has been almost no assessment of the variability in respiration with trip characteristics (including correlation with exposure concentrations).

Bicyclists’ pollution uptake doses are affected by the intake dose, pollutant characteristics, breathing depth and pathway, and other individual and physiological factors. Uptake rates tend to increase with exertion level, affecting bicyclists more than motorized travelers. There are clear links between traffic-related air pollution exposure and negative health outcomes in urban populations. However, the health effects of chronic daily air pollution uptake by bicyclists are still unknown. More research is needed on health impacts of pollution exposure because some studies of bicyclists’ biomarkers show significant acute respiratory effects while other studies show insignificant effects.

https://www.tandfonline.com/doi/full/10.1080/01441647.2014.897772

2 Curtiram

Boa tarde.
Não são necessários estudos quando se utiliza o senso comum. Os carros mais recentes possuem filtro de habitáculo que, embora quase não filtrem as micro partículas, (para ja) impedem muitos poluentes de entrarem no interior do carro. O condutor não vai em esforço, logo as trocas gasosas são superficiais. Já de bicicleta não é bem assim. O ciclista, por ir com os pulmões em carga, devido à pedalada e circulando ao lado ou atrás dos carros absorve muitos mais poluentes, as micro partículas e os outros que ficam nos filtros de partículas dos automóveis.

1 Curtiu

Um filtro de habitáculo com carvão activado e categoria HEPA consegue filtrar as partículas PM10 e grande parte das PM2.5

2 Curtiram