Headaches, wheezing, runny noses, streaming eyes and flu-like symptoms may have an altogether new culprit. Experts are beginning to blame the popular crop Rapeseed.
Rapeseed, also known as oilseed rape, rape, rappi, rapa and canola, is a tall, bright yellow flowering member of the mustard/cabbage genus. It was brought to England in the 14th century and is now the third leading source of vegetable oil in the world, accounting for 16% of the world’s consumption. The oil is used in cooking and to make alternative bio-fuels. Due to demand outstripping supply, the UK is planting bumper crops of the heavily flowered plant this year.
With their numerous bright and colourful yellow flowers, they certainly do brighten up the countryside, but there are serious concerns that they are causing some asthmatics and hay fever sufferers more misery than usual.
The season to watch out for in the UK is mid-April to June, when the flowers are in full bloom. Whilst there are no specific scientific studies on the matter, anecdotal evidence suggest that the effects of hay fever have worsened in line with Britain’s ever increasing amount of rapeseed crops. Farmer’s produce over 2 million tons of the crop per year, compared with just a few thousand tons in the 70’s. Worldwide production exceeds 50 million tons.
Sufferers would be forgiven for assuming their symptoms are caused by the huge amounts of pollen these plants produce, but interestingly enough, this isn’t the case. The National Pollen and Aerobiology Research Unit in Worcester reports that only 1 in 25 people tested for rapeseed allergies, react to the plant itself. Rape pollen is an insect pollinated crop, rather than wind pollinated. Rape pollen rarely manages to travel more than 200 metres away from its source. The answer lies in the gases the plants produce.
Rapeseed has a particularly strong aroma which can be smelt easily when driving/walking past the crops. The plant releases volatile organic compounds, which are emitted by oils when it blooms. A study at the Scottish Crop Research Institute in Dundee found that 22 different volatile compounds were released by the flowering plant, many of which are known to cause respiratory problems. Chemicals called terpenes, organic disulfides and aldehydes are the nastiest culprits. Maureen Jenkins of Allergy UK stated ‘Rapeseed produces volatile oils in the atmosphere which irritate sensitive airways. Anyone with hay fever or asthma may find symptoms worsening if passing a rapeseed field because of these volatile oils in the air.’
Why is it a bigger problem in the UK than that of other countries?
Heavy rainfall in the winter months makes the humidity high in the UK. When humidity is low, pollen particles will sink to the floor and be less of a problem. When humidity is high they remain in the air for extended periods of time.
What can sufferers do to ease their symptoms?
Keep car doors closed when driving about in the rapeseed flowering season and if you have crops close to your home, keep windows and doors shut. A nasal spray may ease blocked airways and taking antihistamines suitable for hay fever may also soothe the most unpleasant symptoms. As with any allergy, it is always advisable to seek the advice of your doctor first.
Sources: http://en.wikipedia.org/wiki/Rapeseed, http://www.bloomberg.com/news/2010-11-22/eu-rapeseed-oil-market-outlook-is-firm-on-demand-hgca-says.html, http://www.dailymail.co.uk/health/article-458357/Runny-eyes-wheezy-chest-Blame-Britains-crops-rapeseed.html