The air quality of south China's Guangdong Province is getting worse with record hazy days registered last year, a newly-issued environment report shows.

The province, which borders Hong Kong, recorded an average of 75.7 days of haze in 2007, a "marked increase" over normal years and "the most" since 1949 when the New China was founded, according to the report on atmospheric composition of Guangdong released by the provincial meteorological bureau.

Haze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky and diminish visibility.

In total, 27 major cities and counties set records in terms of hazy days last year. The situation was relatively more grave in the Pearl River Delta region in eastern Guangdong. Most cities and counties there saw more than 100 hazy days, the report said, citing 213 days in Dongguan City and 238 days in Xinhui City.

Enping City in Guangdong's northwest recorded 240 hazy days last year, the most in the province, the report said.

Last month saw an average of 11.8 hazy days in Guangdong, the most in 2007, and 22 such days in the provincial capital Guangzhou, the highest since 2000, according to the report.

"The serious situation of hazy days shows the atmospheric pollution in Guangdong, especially in urban areas, is worsening," it said.

Industrial discharge and auto exhaust were largely blamed for the air pollution, according to Wu Dui, an atmospheric studies expert from the Guangdong Provincial Meteorological Bureau.

He said haze lingering over the Pearl River Delta region was mainly caused by lower atmospheric pollutants brought by air currents along the coastline from Hong Kong, Shenzhen and Dongguan; the haze was rarely blown from the region to Hong Kong -- only one to three days in a year.

In addition, the photochemical pollution was grave and the ratio of fine particles was increasing in the atmosphere over the sky of the delta region. This not only greatly reduced visibility in hazy days, but also did harm to people's health by damaging their respiratory tracts, heart and blood vessels, liver and lungs, Wu said.

The term fine particles -- an air pollution -- refers to tiny particles or droplets in the air that are 2.5 microns or less in width.

"The environment authorities should issue a pre-warning of fine particles and give timely health advice to the public in addition to publishing air pollution results," Wu said.

"It may take at least 20 or 30 years to bring the haze under control. Cities in the delta region should join in fighting air pollution instead of acting by themselves," he added.