NB air quality averages 99% compliance with provincial objectivesAir quality in New Brunswick continued to show improvement in 2002, based on data in the province's sixth annual air quality report, Air Quality Monitoring Results in New Brunswick for the year 2002, released earlier this month.
"I am glad to report that the average compliance with established air quality objectives remained greater than 99% in 2002," said Environment and Local Government Minister Brenda Fowlie. "The air quality overall in New Brunswick continually improves and looking to the future, the department is focused on ensuring further improvement."
The report presents summary statistics derived from measurements of air contaminants at 54 monitoring sites in eight regional monitoring networks across the province, plus additional statistical data. In New Brunswick, air quality objectives are established for carbon monoxide (CO), sulfur dioxide (SO2), hydrogen sulfide (H2S), nitrogen dioxide (NO2) and total suspended particulate (TSP).
As well, acid rain was measured at 13 additional sites, and inhalable particulate matter (PM10 and PM2.5), volatile organic compounds and mercury in air and precipitation were also monitored at some locations, although no objectives for these substances were in effect in New Brunswick in 2002.
Some of the report's highlights are summarized below.
*There were no exceedances of objectives for NO2 or CO at any of the provincial monitoring sites.
*There were 80% fewer exceedances of the H2S objective in 2002 than in 2001.
*SO2 exceedances were similar to those of 2001, while ozone exceedances were slightly higher.
*Total volatile organic compound (VOC) concentrations in 2002 decreased at both the Forest Hills and Champlain Heights (Saint John) monitoring sites.
*For particulate matter, there were no exceedances for PM10, but exceedances for PM2.5 were higher than 2001, primarily due to an episode in July when forest fire smoke affected the province.
For the second year in a row, the department used its mobile air quality monitoring vehicle to investigate conditions in locations not covered by permanent monitoring sites. Results include data collected in Saint John from January to April, and in LamËque (in the Acadian peninsula) during the summer. Notable results included some exceedances of total reduced sulfur and SO2 at the Saint John location, and numerous exceedances of total reduced sulfur in LamËque. Evaluations of both locations are continuing.
A review of air quality trends at sites with long records indicates that since the late 1970s and 1980s, air quality has improved for all pollutants currently being measured, with the possible exception of ground level ozone, for which no clear trend is apparent. Levels of SO2, TSP and PM10 have fallen significantly over the past 15-20 years, while CO and NO2 levels have generally declined as well. Total VOC concentrations in 2002 were lower at both Forest Hills and Champlain Heights (in Saint John) than in 2001, as were concentrations of potentially hazardous VOCs such as benzene.
Monitoring data for the gasoline additive MTBE in Saint John since 2000 showed higher results at Champlain Heights than at Forest Hills, although there was no clear trend over the two-year period.
A comparison of annual average concentrations of major pollutants in New Brunswick with recent results from other centres across Canada showed that New Brunswick sites tend to have lower NO2 and PM10 concentrations, whereas results for most other substances tend to fall in the middle of the national range. A possible exception is ozone, with some New Brunswick sites having among the highest values in Canada.
Although acid deposition has generally declined since the early 1990s, acid rain impacts continue to be of concern in the province, particularly in southwestern districts. Sulfate in precipitation, a key indicator of acid rain, was about 10% lower in 2002 than in 2001.
In 2002 the annual average concentration of mercury in precipitation at the St Andrews monitoring site was the lowest recorded (since 1996). There is little evidence of any trend for mercury in ambient air over the same time period.
The full Report on Air Quality Monitoring Results in New Brunswick for the year 2002 may be requested from the Sciences and Reporting branch, Department of Environment and Local Government, PO Box 6000, Fredericton, NB E3B 5H1; 506/457-4844,