A key measure of air pollution quintupled in the first hours of the lunar new year in 2013 due to the arsenal of fireworks that residents shot off at midnight for the holiday festivities, local media reported Wednesday.

The pollution data, issued Tuesday by the Shanghai Environmental Monitoring Center, showed air pollution levels spiked just after midnight on the first day of the lunar new year in 2011, 2012 and 2013, leading to calls to rein in the tradition of shooting off fireworks during the Spring Festival holiday.

By tradition, residents shoot off fireworks at midnight on the first day of the lunar new year and at midnight on the fifth day to welcome the god of wealth.

The environmental monitoring center's data showed levels of PM 2.5, PM 10 and sulfur dioxide all spiked at midnight on the first and fifth days of the lunar new year in 2013, according to a report in the Oriental Morning Post. It also showed that levels of the latter two pollutants jumped at the same times in 2011 and 2012.

The monitoring center did not start releasing data on PM 2.5, which stands for particulate matter no more than 2.5 microns in diameter, to the public until June 2012, so PM 2.5 figures for the previous lunar new years were presumably unavailable.

On the eve of the last lunar new year, February 9, the level of PM 2.5 rose from 81.4 micrograms per cubic meter at 8 pm to 523.7 micrograms per cubic meter at 2 am the following day, according to the report. The latter figure is nearly seven times the national limit.

The reading had fallen back to less than 50 micrograms per cubic meter by 6 pm on February 10.

PM 2.5 is considered especially dangerous because the small size of the particulates allows them to lodge deeply in the lungs, where they can aggravate respiratory conditions.

The primary sources of PM 2.5 are automobile exhaust, chemical plant emissions and road dust.

Internet users and experts called for residents to set off fewer Spring Festival fireworks, or end the practice entirely.

Although shooting off fireworks contributes very little to overall air pollution levels in the city, residents should do their part to improve the air quality, said Li Ming, a delegate of the Shanghai Municipal People's Congress.

Li said he plans this year to submit a proposal that bans the sale of fireworks and prohibits residents from setting them off in more parts of the city.

According to Shanghai Firework Safety Management Regulations, residents cannot set off fireworks within Inner Ring Road or close to government office buildings, airports, military installations, kindergartens and hospitals.

The rules, however, have been widely ignored, especially during the Spring Festival holiday.

It is unrealistic to ban fireworks because setting them off has become a popular tradition among residents, said Dai Xingyi, a professor in the Department of Environmental Science and Engineering at Fudan University.

Shanghai fire prevention officials plan to cut the number of authorized stalls that sell fireworks by 400 this year, according to a report in the Xinmin Evening News.