A case-control study of persons with elevated blood levels of dieldrin

We studied 31 employees (26 men, five women) from three firms, between the ages of 16 and 56 years, who had been exposed to trichloroethylene (TRI) from 1 month to 35 years, mean 7 years. To objectify the actual solvent-exposure we performed "biological monitoring" and determined TRI- and the metabolites trichloroethanol (TCE) and trichloroacetic acid (TCA) in blood- and/or urine-samples. The following concentrations were found in the urine-samples: TCE 19.0-357.0 mg/g creatinine, median 90.0; TCA 2.0-201.0 mg/g creatinine, median 48.0; TTC (TCE + TCA) 31.0-416.0 mg/g creatinine, median 112.5. Additionally three results of former urine-analyses in the period 1978-1980 from 10 workers were obtained to calculate "time-weighted-average (TWA)"-levels (TWA-TTC in urine: 53-640 mg/g creatinine). Nerve conduction velocity (NLG)-measurements of motor and/or sensory fibers of the ulnar and median nerve were performed to test peripheral nerve function. Seven employees were excluded. They had possible competitive risks of peripheral neuropathy, or were of less than 10 months exposed. For controls we examined 24 healthy persons of identical sex and age (matched pairs), but without known risks of a peripheral neuropathy. In comparing the nerve conduction velocities there were no significant differences between TRI-exposed and non-exposed persons. Correlation analyses and the individual assessment of the data concerning exposure/dose and effect revealed no signs of a "dose-effect-relationship".

Untersuchungen zur Neurotoxizit�t von Arbeitsstoffen

Triebig¹,

Trautner²,

Weltle³

et al. 1982

Untersuchungen zur Neurotoxizit�t von Arbeitsstoffen

Triebig

Krekeler²,

Goßler

et al. 1981

We examined eighteen workers (three women, 15 men) in a pentachlorophenol (PCP) processing factory, with a mean activity of 12 years. PCP in blood and urine samples was analyzed by gas chromatography. To evaluate the peripheral nervous system the maximal motor as well as sensory nerve conduction velocities of the ulnar and/or median nerve were measured. The PCP-levels in plasma ranged between 0.02 and 1.5 ng/l, median 0.25 ng/l, and in urine between 13 and 1,224 micrograms/l, median 112 micrograms/l, or between 11 and 2,111 micrograms/g creatinine, median 111 micrograms/g creatinine. The median values of the neurophysiological parameters showed a mild degree of slowing in the PCP-collective. In the case of the sensory nerve conduction velocities, this decrease was significant. A dose-effect relationship between internal PCP-load and the different nerve conduction velocities could not be demonstrated. The individual evaluation of the toxicological and neurophysiological results gave hints that in some cases decreased nerve conduction velocity is caused by chronic exposure to PCP.

Effect of occupational exposure to aldrin on urinary d-glucaric acid, plasma dieldrin, and lymphocyte sister chromatid exchange

Edwards

Priestly

1994

The effects of exposure to the chlorinated cyclodiene termiticide aldrin was evaluated in pest control workers potentially exposed to this material. Sister chromatid exchange (SCE) frequencies were not elevated in workers handling aldrin. This is consistent with the fact that chlorinated cyclodienes are not genotoxic. Plasma dieldrin concentrations (up to 250 ng/ml) confirmed exposure in workers actively performing termiticide treatments and in maintenance and store workers, when compared with unexposed control workers (median concentration, 4.8 ng/ml). Urinary D-glucaric acid (DGA), an index of hepatic enzyme activity, was elevated in pesticide-exposed groups but urinary DGA was poorly correlated with plasma dieldrin level. This indicates that concurrent exposures of these groups to other pesticides may have influenced mixed-function oxidase metabolic activity.