Delayed eye and other consequences from exposure to methyl isocyanate: 93% follow up of exposed and unexposed cohorts in Bhopal

• Published in: British Journal of Industrial Medicine 1990-08, Vol.47 (8), p.553-558
• Main Authors: Andersson, N, Ajwani, M K, Mahashabde, S, Tiwari, M K, Muir, M K, Mehra, V, Ashiru, K, Mackenzie, C D
• Format: Article
• Language: English
• Subjects: Accidents, Occupational; Adolescent; Adult; Age groups; Air; Biological and medical sciences; Cataract - chemically induced; Cataracts; Child; Child, Preschool; Cohort Studies; Cyanates - poisoning; Environmental Exposure; Environmental pollutants toxicology; Eye Diseases - chemically induced; Eyelids; Eyes; Female; Follow-Up Studies; Humans; India; Infant; Infections; Isocyanates; Male; Medical sciences; Middle Aged; Referents; Toxicology; Trachoma; Visual acuity; Visual Acuity - drug effects
• ISSN: 0007-1072; 1351-0711; 1470-7926
• DOI: 10.1136/oem.47.8.553

A follow up study three years after exposure to methyl isocyanate in 93% of exposed survivors and "control" residents in 10 Bhopali communities showed an excess of eye irritation, eyelid infection, cataract, and a decrease in visual acuity among the exposed people. Breathlessness was twice as common in the heavily exposed clusters as those with lower exposure, a trend that could not be explained by different age or smoking patterns (OR 2.05, 95% CI 1.36-3.08). Case referent analysis of outpatient attendances at Bhopal Eye Hospital, considering patients with severe refractive errors and astigmatism as "controls," showed a 40% increased risk of trachoma, 36% increased risk of other lid infections, and 45% increased risk of irritant symptoms among previously exposed people. "Bhopal eye syndrome" may thus include full resolution of the initial interpalpebral superficial erosion, a subsequent increased risk of eye infections, hyperresponsive phenomena (irritation, watering, and phlyctens), and possibly cataracts. It remains to be confirmed whether this reflects a more generalised disease as a consequence of previous exposure to methyl isocyanate or whether it is only the eye that is affected.