Respiratory symptoms in children at schools near a foundry

A survey was carried out in response to complaints of increased respiratory symptoms in children at schools near a foundry in Walsall, West Midlands. Air monitoring around the factory had shown concentrations of formaldehyde most of which were orders of magnitude below the current occupational exposure limit of 2.5 mg/m3, although concentrations up to 0.3 mg/m3 had been recorded over short periods. The study sample comprised children aged 6.8-7.8 years from 39 schools in the borough. Information about respiratory symptoms and potential risk factors for respiratory disease was elicited from parents by a self administered questionnaire. Data were obtained on 1334 children, a response rate of 81.8%. The prevalences of reported wheeze (11.1%), breathlessness (7.7%), and chest discomfort (8.6%) were similar to those in an earlier survey carried out in Southampton by the same method at the same time of year. Cough (prevalence = 18.4%) and chestiness at night (14.6%) were significantly less common than in Southampton. When sex, social class, housing tenure, passive smoking, and parental history of asthma were taken into account, the prevalences of symptoms at schools within one mile of the foundry were generally lower than in other parts of Walsall. These findings give no support to the hypothesis that foundry emissions cause respiratory disease in children, although an adverse effect in a few sensitive children cannot be ruled out.