Some sufferers are so disabled they cannot work, or have to change jobs. About 200 substances or 'respiratory sensitisors' have been identified as agents which can trigger asthma. The Health and Safety Executive, the Government's safety inspectorate, has launched a year-long awareness campaign for industry.
'Occupational asthma can be an extremely distressing and a life-threatening disease. Respiratory sensitisors are encountered in a wide range of industries including agriculture, food manufacture, electronics, metal manufacture, plastics and chemical processing and woodworking,' Dr Tim Carter, director of Medical Services and Field Operations at the HSE, said.
He advised employees to be aware of the first signs of an allergic response, which might include coughing, wheezing or shortness of breath. 'Classic occupational asthma is experienced at the end of the working day but gets better at the weekend,' he said. He said the first line of defence was to avoid becoming sensitised.
Asthma is largely seen as a condition that starts in childhood and incidence in children has doubled since the mid 1960s, according to the National Asthma Campaign, which supports the HSE initiative. These increases are put down to increased diagnosis, but also to air pollution, particularly that caused by vehicle emissions, and to modern living. Central heating, fitted carpets and double glazing provide a good environment for the house-dust mite, a known cause of asthma.
But many people are unaware that asthma can also start in adult life, and for the past five years the HEA has been working with chest physicians around the country to identify, for the first time, the scale of the problem. The 1,000 new cases a year are only those severe enough for the sufferer to be referred to a hospital consultant for treatment.
Dr Carter said there were two types of allergens, those from specific chemicals and those found in proteins. 'Among chemicals, isocyanates, used in paint spraying, a number of ingredients used in dyeing and soluble salts of nickel and platinum are established causes. With the proteins the food and farming industries using hay, flour and grains will be involved, wood dust is another,' he said.
Dr Carter said that the first line of defence was to remove the allergen if possible. When that was impossible, then good ventilation would often provide the solution. 'Preventive clothing is a last resort,' he added.
Preventing Asthma at Work, How to Control Respiratory Sensitisors; HSE Books, PO Box 1999, Sudbury, Suffolk CO10 6FS; and Dillons; pounds 6.25.
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