Standing or sitting too near a barbecue could give you cancer because the skin absorbs tumour-triggering chemicals - even if you're fully dressed.

Oils in the smokey fumes makes the skin more porous to the compounds and are more likely to enter the body in this way than by breathing them in through the lungs.

Eating barbecued foods is the biggest source of the chemicals, followed by absorption through the skin and then breathing in the barbecue smoke, the Chinese team said.

And as the British barbecue season gets into full swing, revellers have been advised to wash their clothes straight away - to get rid of the particles.

The study found people who sat around an outdoor grill were exposed to compounds called PAHs (polycyclic aromatic hydrocarbons) - through their skin.

They are produced from the burning of organic substances such as coal, petrol and wood.

They also form when meats are cooked in high temperatures - such as pan-frying or grilling.

Exposure to these chemicals can cause respiratory diseases and DNA mutations and have been linked with an increased risk of certain cancers.

But most studies have focused on exposure to PAHs through food or in the air - rather than through the skin.

The new study published in Environmental Science and Technology found people absorbed higher amounts of PAHs through their skin than by breathing them in.

Professor Eddy Zeng, of Jinan University in Guangzhou, said: "Although BBQ may not be a daily activity, it is perhaps one of the most popular outdoor events around the world.

"Barbecue not only improves the flavour of foods but also provides a venue for get-togethers of families and friends.

"Households in the United Kingdom and Europe barbecue more than 10 times a year with a preference for charcoal as a fuel source."

His study looked at data from 20 men attending a barbecue for two-and-a-half hours in China who were divided into three groups to provide varying degrees of exposure to the food and smoke.

After analysing urine samples from the volunteers the researchers found - as expected - diet accounted for the largest amount of PAH exposure.

But the skin was the second-highest exposure route - followed by inhalation.

They said oils in barbecue fumes likely boost skin uptake of PAHs The team also found clothes may only reduce skin exposure to PAHs over the short term.

Once clothing is saturated with barbecue smoke the skin can take in considerable amounts of PAHs from them.

They suggest washing clothes soon after leaving a grilling area to reduce exposure.

Professor Eddy Zeng, an expert in environmental pollution at Jinan University in Guangzhou said absorption of PAHs through the skin has not been adequately addressed despite their "ubiquity and carcinogenity."

Prof Zeng said: "In the case of BBQ fumes skin absorption was a more important pathway for intake of PAHs than inhalation."

One group of participants ate barbecued meats and were exposed to smoke through the air or skin.

The others didn't eat any meat and were either exposed to the smoke in these normal ways or wore a special mask to prevent inhalation.

The researchers collected urine samples from the participants before and after the BBQ and also collected samples of air, food and cotton clothing to analyse for PAHs.

They said in a press release: "With summer coming, it's only a matter of time before the smells and tastes of barbecued foods dominate the neighbourhood.

"But there's a downside to grilling that can literally get under your skin."

In the US three-in-four adults own a barbecue - and nearly half of them grill once or twice a week in summer.

Eating grilled foods has previously been associated with increasing the risk of cancer because of PAHs.

But an earlier study by Prof Eddy Zeng's team found bystanders near barbecues were likely exposed to considerable amount of the chemicals through skin exposure and inhalation.

This was even if they didn't eat the grilled foods.

The latest findings build on that - more precisely quantify skin uptake of PAHs from barbecue fumes and particles.

Prof Zeng said: "Polluted clothes may become a persistent exposure source under certain circumstances and should be treated properly to reduce skin absorption of contaminants."