Nephrotoxic effects of silica dust

The hypothesis of chronic nephropathy in association with silica exposure is supported by several epidemiologic studies. Our study investigates the adverse effects of silica exposure on the kidneys, in both silicotic and non-silicotic workers. The studied population included an exposed group [n=112], working as millers in the manufacture of bricks, and in underground mining, and a referent group [n=51] matched for age, sex and socioeconomic status. Our results revealed renal affection caused by silica exposure which was proved to occur earlier than chest manifestations of silicosis and that laminin levels serve as an early indicator of renal dysfunction. Also laminin levels show positive correlation with the duration of exposure

Pesticides and asthma

In this study we try to prove and evaluate the acute and chronic effects of pesticides on respiratory system among pesticide applicators. They were applicators of different types of pesticides [organophosphates, carbarnates, pyrethroides and or-ganochlorine] living in an Egyptian village [150 Km south to Cairo]. Respiratory symptoms were reported in about 66.5% of the applicators and only in 33.4% of controls [highly significant p < 0.01]. Chest examination revealed that 21.7% of the applicators and 11.4% of the control subjects had respiratory signs. Analysis of the ventilatory function results showed a significant ventilatory defect [p < 0.05] among applicators when compared to the control, these were in the form of obstructive defects [doubled] and restrictive defect [5 folds increase]. The relation between the duration of exposure among applicatos and the ventilatory functions showed that the more they were exposed to pesticides the higher the incidence of ventilatory function changes. The challenge test was done to 38 applicators and 63 control subjects, with 39.5% +ve in applicators and only 17.9% in control, and the result was significant. Also, the serum cortisol level and cholinesterase activity were more depressed among applicators than in controls. We concluded that people with chest problems, especially asthma and COPD, should avoid exposure to pesticides. Challenge test with methacholine should be done as screening test to all applicators before exposure and positive subjects should be excluded