Christmas trees could be to blame for a range of health complaints over the festive¹ season, according to new research.

新研究显示，圣诞树可能是圣诞节期间一连串身体不适的罪魁祸首。

Don't be too quick to judge those who feel under the weather（不舒服） over the festive period – rather than seasonal² overindulgence, it could be their Christmas tree making them ill.

The traditional centrepiece decoration has been blamed for triggering a range of health complaints, from wheezing³（哮喘） and coughing to lethargy（昏睡） and insomnia⁴.

The condition – "Christmas Tree Syndrome⁵" – is caused by mould growing on the trees, whose spores⁶（孢子） lead to problems when breathed in.

It has been discovered by scientists from Upstate Medical University, part of the State University of New York, who carried out research after observing a peak in respiratory（呼吸的） illnesses in the weeks either side of December 25.

The team analysed clippings from 28 Christmas trees including needles and bark, from a range of species, and found 53 cases of mould.

Of these, 70 percent can cause symptoms including itchy noses, watery⁷ eyes, coughing, shortness of breath, chest pains, sinus（静脉窦） congestion⁸, feelings of fatigue⁹ and problems sleeping.

Some of the mould identified can even lead to long term lung problems and conditions such as bronchitis（支气管炎） and pneumonia¹⁰.

The mould occurs on the trees naturally, but thrives in the warm conditions of a well-heated home at Christmas.

The team, writing in the Annals of Allergy¹¹, Asthma¹² and Immunology, also reported another study which found that after a Christmas tree has been on display for a fortnight, the number of airborne mould spores increases from 800 per 35 cubic feet to 5,000.

Dr Lawrence Kurlandsky, who led the research, said he had treated patients where there was a clear link between their illness and their Christmas tree.

For those not wishing to opt¹³ for this extreme option, Dr Kurlandsky has two other pieces of advice for those wishing to avoid falling victim to Christmas Tree Syndrome.

Firstly, hose down（用水管浇） your tree in the garden and leave it to dry before bringing it inside. Then, to further reduce your chance, remove it swiftly after Christmas Day, long before the traditional Twelfth Night（主显节前夕） .