The ordinary work environment increases symptoms from eyes and airways in mild steel welders

We aimed to follow diary-registered symptoms from eyes and airways in mild steel welders and relate them to different exposure measures. Furthermore, we would clarify the influence of possible effect modifiers. Non-smoking welders with (N = 74) and without (N = 32) work-related symptoms the last month were enroled. Symptoms and work tasks each day for three two-week periods during 1 year were obtained. Respirable dust (RD) was measured 1 day each period for each worker. The personal daily exposure was assessed as: (1) days at work, (2) welding time and (3) estimates of RD from welding and grinding, calculated from diary entries and measurements. Only 9.2 % of the particle measurements exceed the Swedish occupational exposure limit (OEL; 5 mg/m(3)). Days at work increased the risk of symptoms studied: eyes: 1.79 (1.46-2.19), nasal: 2.16 (1.81-2.58), dry cough: 1.50 (1.23-1.82) and wheezing and/or dyspnoea: 1.27 (1.03-1.56; odds ratio, 95 % confidence interval). No clear dose-response relationships were found for the other exposure estimates. Eye symptoms increased by number of years welding. Nasal symptoms and dry cough increased having forced expiratory volume in first second below median at baseline. Wheezing and/or dyspnoea increased in winter, by number of years welding, having a negative standard skin-prick test and having a vital capacity above median at baseline. The current Swedish OEL may not protect welders against eye and airway symptoms. The results add to the evidence that welders should be offered regular medical surveillance from early in the career.