Food production hit by increasing ozone levels

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>http://foodqualitynews.com/news/ng.asp?id=55267 & n=wh42 & c=wokvpgxagwnympq

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>Food production hit by increasing ozone levels

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>08/10/2004 - Dr Lisa Emberson of the University of York tells Anthony

>Fletcher why high ozone concentrations could cost food producers

>millions in damaged crops.

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>Increased ozone concentrations at ground level may be causing millions

>of pounds of damage to UK food crops, according to a University of

>York researcher.

>

>Building on a previous study on ozone concentrations in the

>environment, which estimated that in 1990 alone the UK lost £130

>million in crops due to ozone taken up by plants, Dr Lisa Emberson of

>the Stockholm Environment Institute at York has been developing new

>methods to calculate the amount of ozone that agricultural crops absorb.

>

>Her figures incorporate factors such as species-specific and

>environmental conditions, such as growing season, drought and

>humidity, which, in combination with ozone concentrations, determine

>crop susceptibility.

>

>Applying this new method for the UK, the loss of production in two

>staple crops, wheat and potato, translates into economic losses of

>approximately £70 million and £14 million respectively. The scale of

>damage varies by region according to ozone levels, climate, and crop

>distribution.

>

>The figures only take into account the effect on the quantity or yield

>of the crop, and do not include other ozone damage such as leaf injury

>or poor grain quality.

>

> " The increase in ozone levels is due to human activity, " Emberson told

>FoodProductionDaily.com. " It is a secondary pollutant. It is formed

>when nitrogen oxides react with volatile organic compounds (VOCs) that

>are emitted into the atmosphere through fossil fuel burning and

>various industrial processes. "

>

>Before industrialisation, annual mean ozone concentrations were

>between 10 to 15 parts per billion (ppb). Concentrations have now

>risen to around 30 ppb, and hot sunny days in the UK lead to

>concentrations that can exceed 100 ppb.

>

>Ozone is a naturally occurring atmospheric gas. High up in the earth's

>atmosphere, it plays a crucial role in filtering out harmful

>ultraviolet radiation that would otherwise damage life on earth. But

>at ground level, it damages human health, vegetation and materials and

>is also a potent greenhouse gas.

>

> " We've tried to accurately evaluate the economic threat. Food

>producers are probably not aware that ozone is a regional pollutant,

>which makes it difficult assess, " said Emberson.

>

> " We've tried to assess the absorbed dose of ozone and calculate the

>exact cost this has on crop yield. "

>

>Emberson, who is co-editor of the recently published `Air Pollution

>Impacts on Crops and Forests,' does believe that progress, at least in

>Europe, is slowly being made to reduce VOC emissions that contribute

>to excess levels of ozone. But she is concerned that while peak

>concentrations seem to have been reduced, background concentrations,

>especially in Asia, appear to be on the increase.

>

> " Rather than being exposed to short sharp bursts, crops are

>increasingly subject to more long term exposure to high ground levels

>of ozone, " she said. " This could potentially be very serious. "

>

>Emberson says that it is vital that food producers fully understand

>the combined stresses of ozone pollution and climate, especially given

>the projected increase in background ozone concentrations and changes

>in climate likely to occur in coming decades.

>

>Work is now underway to assess the threat to maize, tomato, sunflower

>and sugar beet – economically important crops that are sensitive to ozone.

>

>The Stockholm Environment Institute at York (SEI–Y) is one of the

>constituent centres of the Stockholm Environment Institute, an

>independent, international research organisation committed to the

>implementation of practices supportive of global sustainable development.

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