Air quality in coastal areas was generally better than in the central and northern region of the Pearl River Delta in the first half of 2007, a report has found.

The Environmental Protection Department and Guangdong Environmental Protection Bureau today announced the results of the report on the monitoring results of the Pearl River Delta Regional Air Quality Monitoring Network, which covers the first half of 2007.

It said clearer conditions on the coast could be attributed to better dispersion of pollutants.

The network measures concentrations of sulphur dioxide, nitrogen dioxide, ozone and respirable suspended particulates. The overall concentrations of most pollutants were generally higher in winter.

Heavier rainfall and the relatively clean maritime airstreams that prevail over the delta region with southern monsoon accounts for a lower level of pollution in summer.

Monthly variations in the concentration of pollutants change from year to year, requiring long-term monitoring before a general pattern can be established.

Monitoring results for all of 2007 will be available in April.