Pyromellitic dianhydride (PMDA) may cause occupational asthma.

INTRODUCTION: Anhydrides are widely used as cross-linking agents in epoxy resins and alkyd production, for example, as coatings and adhesives in plastic products. Sensitisation to several anhydrides is known to cause occupational asthma. There are indications that the lesser known pyromellitic dianhydride (PMDA) can cause irritative respiratory symptoms and possibly asthma. We report three cases of workers from a plastic foil manufacturing plant, who developed asthma when exposed to PMDA during specific inhalation challenge (SIC). METHODS: SIC was performed over 2 days according to recommendations of European Respiratory Society. Lactose powder was used in control challenges and a mixture of 10% PMDA and 90% lactose powder in active challenges. RESULTS: All cases experienced a delayed decrease in forced expiratory flow in 1 s (FEV1) 4-12 hours after active challenge. FEV1 decreased by 19%, 15% and 16%, respectively. After 21 hours, FEV1 decreased by 24% in one worker. DISCUSSION: Respiratory symptoms after working hours may represent delayed work-related asthma. During SIC, the three patients developed lower respiratory symptoms and a delayed decrease in FEV1 which suggest sensitisation. The mechanism of anhydride-related asthma is not well understood. Anhydrides are known irritants and hence an irritative response cannot be excluded. The company improved ventilation and enforced the use of respiratory protection equipment, and finally phased out PMDA. Occupational workplace risk identification may help to identify exposures. SIC can contribute to improving working conditions, by identifying and confirming asthmogens in the environment.

Population screening for coronary artery calcification does not increase mental distress and the use of psychoactive medication.

PURPOSE: Detection of coronary artery calcification (CAC) has been proposed for population screening. It remains unknown whether such a strategy would result in unnecessary concern among participants. Therefore, we set out to assess whether CAC screening affects the psychological well-being of screening participants. MATERIALS AND METHODS: A random sample of 1825 middle-aged subjects (men and women, 50 or 60 y old) were invited for health screening. The European HeartScore was calculated, and a CAC score was measured using a cardiac computed tomography scanner. Therapeutic interventions as a result of the observations were at the discretion of the individual general practitioner. Before screening and at 6-month follow-up a depression test (Major Depression Inventory) was conducted, and the use of psychoactive medication was recorded. RESULTS: A total of 1257 (69%) subjects agreed to participate. Because of known cardiovascular disease or diabetes mellitus, 88 persons were excluded. Of the remaining 1169, 47% were men, and one half were 50 years old. At 6-month follow-up, significant reductions were observed in the Major Depression Inventory score from 5.3 to 3.9 (P<0.0001) and in the prescription rates of psychoactive medication from 7.1% (83 of 1169) to 6.2% (72 of 1169) (P=0.003). The results were independent of sex, age, HeartScore, CAC Score, and changes in other medication. CONCLUSIONS: A population screening program including CAC score appears to have no detrimental impact on mental distress and does not increase the use of psychoactive medication.