A 2006 report on regional air-quality monitoring has found the air quality to be better in coastal areas than in the Pearl River Delta's central and northern regions. Most pollutants' overall concentrations were generally higher from January to March and from October to December, and fell in June and July.

The Environmental Protection Department and Guangdong Environmental Protection Bureau today announced the Pearl River Delta Regional Air Quality Monitoring Network's 2006 report.

The network measures the concentrations of major pollutants including sulphur dioxide, nitrogen dioxide, ozone, and respirable suspended particulates.

Long-term monitoring is required before a general pattern can be established, the Environmental Protection Department said.

Intermittent high level of pollutants exceeding Class 2 of the National Ambient Air Quality Standards, applicable to general residential areas, was recorded in all the network's monitoring locations in 2006. This was mainly triggered by weather conditions that heeded pollutant dispersion.

In the long term, the monitoring results will help the two sides to carry out scientific analysis of the air-quality trends in the delta region.

The emissions-reduction measures the two sides are pursuing will have a positive impact on the regional air quality. The Government expects that after the network records more data, the two sides would be able to scientifically assess the measures' impact and effectiveness.

The monitoring results for the first half of 2007 are expected to be available in October.