[A 2-generation fertility study with 1,4-dichlorobenzene in rats]. / 2-Generationen-Fertilitätsstudie mit 1,4-Dichlorbenzol an Ratten.

1,4-Dichlorobenzene (pDCB), dissolved in olive oil, was administered orally to two generations of rats to detect possible effects of the test substance on reproduction (OECD guideline 416). The doses used for the three test substance groups were 30, 90 and 270 mg pDCB per kg body weight. Olive oil was applied to one negative control group. Dose volume was 1 ml per kg body weight for all groups. In both generations the test substance had no effects on: time between beginning of mating and evidence of copulation, time of gestation, fertility index, gestational index, percentage of dams with only dead pups, total number of pups at birth, percentage of pups with positive ear reflex, grasping reflex and orientation reaction, absolute and relative weights of testes, epididymides and ovaries, absolute and relative weights of female kidneys, spleens and livers. In the mid and/or high-dose groups the test substance had an effect on: number of live pups at birth (reduced), number of pups deceased between days of lactation 1 to 4 and 5 to 21 (increased), mean body weight of pups (reduced), erection of ears and opening of eyes (retarded), percentage of pups with positive draw up test (reduced), alterations of the skin (dry, squamous) and ring tails in pups, absolute and relative organ weights of adult males (livers and kidneys: increased; spleens: reduced). Damages to the kidneys in mid- and high-dose groups of both generations are also probably test substance related. At the low dose of 30mg pDCB per kg body weight--equivalent to the actual MAK-value of 450 mg/m3 (exposure by inhalation)--no effects of the test substance were detected on fertility parameters of rats. The next higher dose of 90 mg/kg already caused massive damage in pups. Therefore, a reduction of the actual MAK value should be taken into consideration.

Analysis of human chromosomes after repeated hair dyeing.

Ten volunteers (males and females) each had their hair dyed 13 times at intervals of 3-6 wk. Each volunteer used a single commercial preparation throughout the study. The preparations used contained a mixture of aminotoluenes, aminophenols and hydroxybenzenes and, in some cases, naphthol, as the active ingredients. Lymphocytes of the hair-dyed volunteers and of ten controls matched for age and sex were scored for chromosomal aberrations. The incidence of aberrations did not differ significantly between the controls and the hair-dyed volunteers at any of the nine sampling times (before the first exposure, after the first (sham) dyeing and then after each of the next three and the last four dyeing procedures). An increase in the aberration rate with time was observed both in the controls and in the hair-dyed subjects. The reason for this increase could not be determined. No clastogenic effect of repeated hair dyeing was established in this study.