Catalytic converters
remove harmful pollutants from vehicle emissions
have caused emissions in Western Europe to increase
trap pollutants in the air
have been required in Western Europe since 1993

Explanation:

The effects on health of transport-related air pollution are among the leading concerns

about transport. Research in recent decades consistently indicates the adverse effects

of outdoor air pollution on human health, and the evidence points to air pollution

stemming from transport as an important contributor to these effects.

This book provides a systematic review of the literature on transport-related air

pollution and a comprehensive evaluation of the health hazards of such pollution. It

focuses on air pollution related to road transport (mostly from urban and suburban

passenger and freight transport) and the risks it presents to human health. It also

considers the entire chain of relevant issues: from patterns and trends in activities that

determine the intensity of emissions from transport, to primary emissions and the

formation of secondary pollutants by means of transportation, and fi nally through to

patterns of human exposure to such pollutants. The discussion of the adverse effects on

health considers the results of both epidemiological studies and toxicological assessments

of biological mechanisms.

the correct answer is c