The air pollution which has engulfed parts of China is having an effect on the weather and climate patterns in the rest of the world, according to a study.

Scientists have also claimed that the increased emissions in China are having a "boomerang effect" on the US, as the pollution seen in areas such as Los Angeles are a by-product of outsourcing US manufacturing to Asia.

The study, published in journal Proceedings of the National Academy of Sciences, says the extreme pollution coming mainly from China affects cloud formations, precipitation, storm intensity and other factors and which could eventually impact climate worldwide.

Using climate models and data collected about aerosols and meteorology over the past 30 years, the research also claims pollution from China's manufacturing for export contributes to as much as 24% of the daily sulphate levels in western areas of the US as it drifts over the Pacific Ocean.

According to the study, Los Angeles now sees one extra day of smog a year which exceeds federal health standards as a result of the drifting pollution.

Yuan Wang, a former doctoral student at Texas A&M University, said: "The models clearly show that pollution originating from Asia has an impact on the upper atmosphere and it appears to make such storms or cyclones even stronger.

"Most likely, pollution from Asia can have important consequences on the weather pattern here over North America."

"We've outsourced our manufacturing and much of our pollution, but some of it is blowing back across the Pacific to haunt us," added co-author Steve Davis, a scientist at University of California Irvine.

According to the World Health Organisation (WHO), the average amount of PM2.5 - the most dangerous component of smog - in the air should not be more than 25 micrograms per cubic metre. Parts of China have recently recorded peak levels of more than 1000 PM2.5 in the air.

China's rapid development has caused widespread pollution problems, particularly in urban areas. China's manufacturing of products for export has also expanded by almost 400% between 2000 and 2007.

According to the report, between 17% and 36% of various air pollutants in China in 2006 were related to the production of goods for export, with a fifth of this related to trade between the US and China, which includes the production of TVs and mobile phones.

The report says talks must take place between trading countries in a bid to cut down on global air pollution.

"International cooperation to reduce transboundary transport of air pollution must confront the question of who is responsible for emissions in one country during production of goods to support consumption in another," it said.

Although the study is concerned about the levels of pollution which is affecting western parts of the US, it adds most of LA's smog is down to localised emissions from vehicles and factories.