Chronic effects of paraquat on the lung
An epidemiological study of the health of Sri Lanka (01.01.93)
Senanayake N, Gurunathan G, Hart TB, Amerasinghe P, Babapulle M, Ellapola SB, Udupihille M, and Basanayake V, An epidemiological study of the health of Sri Lankan tea plantation workers associated with long term exposure to paraquat, British Jour-nal of Industrial Medicine 50(3), 257-263, 1993
In Sri Lanka a study was carried out with 85 plantation workers who had been spraying paraquat (usually at concentrations of 0.2-0.08%) over an average period of 12 years. To assess the potential risks from long-term exposures workers’ lungs were tested by meas-uring lung functions (forced vital capacity, maximum expiratory flow volume, peak expira-tory flow, transfer of CO), and the function of liver and kidneys was monitored (blood levels of urea, creatinine, certain enzymes). A larger proportion of spray men (23.6%) had skin damages than unexposed factory workers (11.8%) or general workers (15.2%). The inci-dence of eye damage was similar in spray men and general workers but not reported by factory workers. Nosebleeds occurred in three spray men, one factory worker but not among general workers. It was found there were no statistically significant or clinically im-portant differences between the groups of workers for any measured parameter except for a certain enzyme. Aspartate transferase activities in blood were positively associated with the total number of spraying days and number of spraying days during the past five years (statistically significant). The increase in aspartate transferase levels was considered to be not clinically significant; this enzyme is used to monitor liver function.
Signs of bronchial obstruction were seen with chest radiography in 9 general and 6 factory workers and in 3 spray men, while respiratory symptoms (mainly cough) were reported by six out of those 9 general workers, by four out of the 6 general workers and by none of the spray me. There was one additional case of a worker with a history of tuberculosis, while two out of 18 workers with signs of airway obstruction in a chest x-ray (one spray man and one factory worker) had no history of smoking. Other symptoms observed were: one gen-eral worker had an irregular pulse; one spray man had abnormal reflexes in both feet (plantar reflex) and increased muscle tone in the upper limb; workers in all groups had headaches, 3 spray men and 1 unexposed worker had nosebleeds, and 9 general workers and 9 spray men had nail damage. The spray solutions used during the study contained 0.04-0.07% paraquat, and the personal hygiene practised by the workers was excellent (frequent washing in running water throughout the day). The lower incidence of damage to skin and nails than reported in other studies was explained by a low spray concentration and very good personal hygiene.
(Conflicting interests cannot be excluded as an author was affiliated to the industry.)
In Sri Lanka a study was carried out with 85 plantation workers who had been spraying paraquat (usually at concentrations of 0.2-0.08%) over an average period of 12 years. To assess the potential risks from long-term exposures workers’ lungs were tested by meas-uring lung functions (forced vital capacity, maximum expiratory flow volume, peak expira-tory flow, transfer of CO), and the function of liver and kidneys was monitored (blood levels of urea, creatinine, certain enzymes). A larger proportion of spray men (23.6%) had skin damages than unexposed factory workers (11.8%) or general workers (15.2%). The inci-dence of eye damage was similar in spray men and general workers but not reported by factory workers. Nosebleeds occurred in three spray men, one factory worker but not among general workers. It was found there were no statistically significant or clinically im-portant differences between the groups of workers for any measured parameter except for a certain enzyme. Aspartate transferase activities in blood were positively associated with the total number of spraying days and number of spraying days during the past five years (statistically significant). The increase in aspartate transferase levels was considered to be not clinically significant; this enzyme is used to monitor liver function.
Signs of bronchial obstruction were seen with chest radiography in 9 general and 6 factory workers and in 3 spray men, while respiratory symptoms (mainly cough) were reported by six out of those 9 general workers, by four out of the 6 general workers and by none of the spray me. There was one additional case of a worker with a history of tuberculosis, while two out of 18 workers with signs of airway obstruction in a chest x-ray (one spray man and one factory worker) had no history of smoking. Other symptoms observed were: one gen-eral worker had an irregular pulse; one spray man had abnormal reflexes in both feet (plantar reflex) and increased muscle tone in the upper limb; workers in all groups had headaches, 3 spray men and 1 unexposed worker had nosebleeds, and 9 general workers and 9 spray men had nail damage. The spray solutions used during the study contained 0.04-0.07% paraquat, and the personal hygiene practised by the workers was excellent (frequent washing in running water throughout the day). The lower incidence of damage to skin and nails than reported in other studies was explained by a low spray concentration and very good personal hygiene.
(Conflicting interests cannot be excluded as an author was affiliated to the industry.)
