Traffic pollution and burning smoky fuels in rural towns have emerged as the greatest threats to Ireland's air quality, according a new report from the Environmental Protection Agency .
While the report, Air Quality in Ireland - Key Indicators of Ambient Air Quality, found that air quality was generally good, it warned that the greatest incidents of pollution in Dublin were due to nitrogen dioxide (NO2) and small particulate matter (PM10), both associated with car-generated pollution.
However, the report's authors said they were surprised to find the highest levels of airborne small particulate matter were recorded in rural towns and villages, which the agency put down to the burning of smoky fuels.
Nitrogen dioxide is associated with impaired lung function in humans and can result in lung infections. Small particulate matter can penetrate deep into the respiratory tract, causing cardiopulmonary disorders.
The highest average levels of nitrogen dioxide were recorded in Dublin's Winetavern Street, at 35 microgrammes per cubic metre. This was close to the EU accepted limit of 40 microgrammes per cubic metre and was described by the report's authors as "potentially of concern". The report said if levels increased, they could pose a threat to meeting EU targets. However, it noted that NO2 levels were significantly lower at suburban and rural stations.
NO2 emissions are generally found where fuel is burned at a high combustion rate, such as power generators and road vehicles. Dr Ciarán O'Donnell, programme manager with the EPA, said the high levels detected in rural areas was a surprise.
"For the first three months of the year, the results of monitoring at Ennis gave us concern but after that, the [ domestic] burning season ended and the levels fell away."
The ban on smoky fuels relates to the sale of smoky fuels, not burning. Dr O'Donnell ruled out lobbying for a change in the law, remarking that "we would prefer to persuade people".
The EPA also recorded high incidences of PM10 in Co Wexford in a rural area which it ascribed to wind-blown salt coming in from the sea. Other PM10 sources recorded included dust from roads, industrial emissions and natural substances.
The report also found concentrations of ground-level ozone (O3) which is harmful to health, measured in 2006 were higher than recent years, particularly during July when hourly thresholds were exceeded at monitoring stations at Valentia, Co Kerry, Kilkitt, Co Monaghan, Glashboy, Co Cork, and Emo, Co Laois.
Levels of lead in the air were less than permitted limits, likely to have resulted from the exclusion of lead from petrol. Benzene levels were said to be below those recommended by a new marginally stricter limit due to come into force in 2010. The highest average levels of 2.5 microgrammes per cubic metre were recorded at Rathmines in Dublin.
