European Directives for Air Quality: Analysis of the New Limits in Comparison with Asthmatic Symptoms in Children Living in the Oporto Metropolitan Area, Portugal

ABSTRACT

This study analyzes the air pollutant concentrations in the Oporto Metropolitan Area, Portugal, comparing them with the limits fixed by the previous legislation currently in force, as well as by European Union (EU) Directives. The impacts were estimated using the prevalence of asthmatic symptoms and asthma in children as indicators. The objectives were: (i) to evaluate the impact on air quality associated with the reduction of sulphur content in fuels, (ii) to compare health impacts associated with SO₂ and particles with the limits fixed by both legislations, and (iii) to assess whether the delayed application of the EU Directives can be associated with health risks. It was concluded that: (i) after the reduction of sulphur content in fuels, a reduction of 60% of the annual averages of SO₂ concentration was observed, as well as a decrease in the rates of asthmatic symptoms and asthma in children, (ii) the limits fixed by the previous legislation do not protect against health impacts of SO₂ and particles, but the new EU Directives are protective; the EU limits for PM₁₀ are very difficult to attain, being probably unnecessarily low concerning the impact on asthmatic symptoms and asthma in children, and (iii) the delayed application of the EU Directives can be associated with unnecessary health risks.

Key Words:

• air pollution
• impact on asthma
• particles
• sulphur dioxide
• air quality legislation.

ACKNOWLEDGMENTS

The authors are grateful to the Comissão de Coordenação e Desenvolvimento Regional do Norte for their collaboration on this study, providing the data of the Air Quality Monitoring Network of the Oporto Metropolitan Area.

Notes

^a Hourly limit: 350 μgm⁻³ not to be exceeded on more than 24 hours a year.

^b Daily limit: 125 μgm⁻³ not to be exceeded on more than 3 days a year.

^a Daily limit: 50 μ gm⁻³ not allowed more than 35 exceedances (10% of the total year days) for 2005 and not more than 7 (2%) for 2010.

^b Monitored only during 4 months.