Damage by anatomical area
The damage to the respiratory system and particularly the lungs comprises the most obvious and very significant part of the overall health damage. Bronchial asthma or reactive airways dysfunction syndrome, chronic obstructive airways disease, recurrent chest infections, bronchiolitis obliterans and restrictive lung disease are the principal effects of exposure. It has also been reported that the incidence of pulmonary tuberculosis among the exposed population is more than three times that of an unexposed population.
Damage caused to the eyes of the survivors has led to corneal opacity (clouding). Prevalence of early-age cataract was three times more among the exposed population compared to the control population. Chronic conjunctivitis, trachoma and fundus changes are some of the other exposure-related eye problems.
Prevalence of mental health disorder was found to be two to three times higher in the gas-exposed population as compared to the control population. Anxiety and neurotic depression were found to be the most common disorders.
The various medical consequences of the Union Carbide disaster have been under-assessed by the ICMR and certain exposure-related injuries have been overlooked, such as post-traumatic stress disorder. A 1989 survey of psychiatric morbidity carried out by doctors from Sir JJ Group of Hospitals, Bombay, found that nearly 40% of those exposed suffered from this disorder.
Pregnancy outcome studies on women who were pregnant at the time of the disaster have shown that the spontaneous abortion rate was almost three times that of the national average. In the exposed population the still birth rate was three times, peri-natal mortality was two times and neonatal mortality was one and a half times more than the comparative national figures.
A study on growth and development of children whose mothers were exposed to the gases during pregnancy revealed that majority of children had delayed gross motor and language sector development. Studies have also presented evidence of chromosomal aberrations of gaps and breaks and increased sister-chromatid exchange indicating likelihood of congenital abnormalities among future generations of the exposed persons.