The car decks on ferries are usually equipped with exhaust
air ventilation. The supply air is generally admitted through the
ramp and the air is removed by exhaust air fans at the other end of
the car deck.
A person carrying out heavy manual work uses up twice as much
air as a person doing light work. As a result, he will inhale a correspondingly
higher proportion of pollutants. Consequently, the work should be
organized so that heavy physical work is avoided in areas where the
pollution level is high. Nobody should be unnecessarily exposed to
hazardous concentrations of exhaust gases.