[Effects of occupational exposure to formamidines on cardiovascular functions]

To understand the possible effects of occupational exposure to formamidines on human cardiovascular function, this study was carried out.

Sixteen farmers spraying chlordimeform, 14 packers packaging chlordimeform and 23 packers packaging mono-formamidine were followed-up pre- and post-exposure. Their urinary excretion of formamidine or its metabolite, as well as air concentrations of formamidine at their work places and their skin contamination with it were measured to estimate the exposure level. Furthermore, 24-hour urinary level of vanillinmandelic acid (VMA) was analyzed among mono-formamidine packers.

Their whole body skin contaminated with 3.240 and 2.142 g/cm(2) of chlordimeform in the sprayers and packers, respectively. Their hand skin contaminated with mono-formamidine at 6.59 g/cm(2) in the packers. It indicated that the major route of exposure to formamidine was skin contamination. Urinary levels of formamidines or their metabolites increased significantly after exposure, reaching 6.194 and 3.378 micromol/L for the sprayers and packers exposed to chlordimeform, respectively, and 2.760 - 3.427 micromol/L for mono-formamidine in the packers. Their heart rates slowed down, P-R and Q-T intervals prolonged and blood pressure reduced after exposure, as compared with those before exposure. Consistency of the results in several studies demonstrated that formamidines could induce changes in the indices for cardiovascular functions under the relatively low exposure levels at present. Decrease of urinary VMA from 0.068 micromol/L pre-exposure to 0.040 - 0.055 micromol/L post-exposure suggested that catecholamine could play a role in these effects.

Formamidines has certain effects on human cardiovascular function. It is suggested that attention be paid to the changes in cardiovascular functions of those exposed in their health surveillance.