Particulate Exposure Onboard Ferryboats And Relationships With Environmental Conditions And Engine Maintenance

We characterized passengers' exposure to black carbon (BC) and particle number (PN) onboard ferryboats in Brazil, complemented with measurements at two piers, a beach, and a lodge on Mel Island. The highest BC exposure was onboard (mean +/- standard deviation: 27.64 +/- 11.62 mu g m(-3)) and the lowest at the lodge (0.39 +/- 0.29 mu g m(-3)). BC exposure was higher than in other ferry studies and on other transport modes in Brazil. Onboard PN exposure was relatively low (1.86 x 10(4) +/- 3.61 x 10(4) cm(-3)), but peaked when engines malfunctioned, being comparable or higher than in other similar studies. The onboard mean PN/BC concentration ratio was low (0.7 x 10(6) particles ng(-1) BC), typical of environments impacted by exhaust emissions. The exhaust plumes were affected by the sea breeze, with a cleaning or polluting effect depending on the wind direction relative to the ferry. Ferryboat emission standards and inspection and maintenance programs are urgently needed.