Improvements in the 32P-postlabelling procedure to quantify bulky aromatic DNA adducts

This contribution describes methodological modifications and improvements that may contribute to inter-assay reproducibility and more accurate adduct quantification for 32P-postlabelling. Firstly, an anion-exchange chromatography procedure was developed to determine the amount of DNA used per assay and to check its purity, in particular to...

Biotransformation of 1,2 dihydronaphthalene and 1,2-dihydroanthracene by rat liver microsomes and purified cytochromes P-450. Formation of arene hydrates of naphthalene and anthracene

Both 1,2-dihydronaphthalene and 1,2-dihydroanthracene were hydroxylated at the benzylic (1-) or the allylic (2-) position by rat liver microsomes and purified cytochrome P-450 enzymes to yield "arene hydrates". Two other classes of metabolites were formed, the dehydrogenation products naphthalene and anthracene, and trans-1,2-dihydroxy-1,2,3,4...

Interactions of halogenated industrial chemicals with transthyretin and effects on thyroid hormone levels in vivo

Previous results in experimental systems have suggested that hydroxylated PCBs may decrease thyroid hormone levels through associative interaction with transthyretin. In the present paper it was investigated whether this property was also shared by various industrial chemicals, mainly pesticides. In total, 65 compounds from 12 chemical groups...

Inhalation exposure to 1,3-dichloropropene in the Dutch flower-bulb culture. Part I. Environmental monitoring

Respiratory occupational exposure to the Z- and E-isomers of 1,3-dichloropropene (DCP) of twelve commercial applicators was assessed. The time-weighted average (TWA) concentrations of DCP ranged from 1.9 to 18.9 mg/m3. On 30% of the observed working days the Dutch occupational exposure limit of 5 mg/m3 was exceeded. Short-term exposure levels...

Polycyclic aromatic hydrocarbons in Dutch total diet samples (1984-1986)

Over a period of 2.5 yr, 221 different food items of a 'market basket' of 18-yr-old males were purchased every 3 months. In total, 10 market baskets were collected. The foodstuffs were prepared by normal methods and combined into 23 commodity groups. Homogenates were prepared from each commodity group, followed by analysis for 17 different...

The occurrence of organic chemicals in the atmosphere of The Netherlands

In this paper concentration levels of various classes of organic chemicals in The Netherlands are reported for the base year 1980. From these levels the average intake of the Dutch population by inhalation was calculated to be ~1.5 g year-1. This gives reason for concern because many of the compounds either seem to exhibit carcinogenic...

Relevance of parameters related to fertility and reproduction in toxicity testing

Toxicity data of 37 compounds tested in both a subchronic study and one or more studies focused on reproduction were evaluated to obtain information on the significance of fertility and reproduction parameters in setting no-effect levels (NEL). It appeared that a) the test system aimed at reproduction and development was more sensitive than the...

Polycyclic aromatic hydrocarbon concentrations in The Netherlands

Starting in the winter 1964-1965, the TNO Research Institute for Environmental Hygiene has determined the PAH-concentrations of the atmosphere at several locations in The Netherlands. Long series of data are available for several stations. The trend in the concentrations is spectacular: the concentrations have fallen from relatively high values...

Survey of the contamination of Dutch coastal water by chlorinated hydrocarbons, including the occurrence of methylthio-pentachlorobenzene and di-(methylthio)tetrachlorobenzene

In 1976 contamination of Dutch coastal waters by organochlorine compounds was assessed by analysing mussels, Mytilus edulis, as an indicator-organism. HCB, dieldrin, endrin, p,p'-DDT, p,p'-TDE and PCB's were detected, and also two new compounds previously unknown in the aquatic fauna. Using gas-liquid chromatography, mass spectrometry and 13C...

The germicidal effect of the open air in different parts of The Netherlands

Using the microthread technique the survival of Escherichia coli MRE 162 in open air was measured in different parts of The Netherlands. The presence of bactericidal compounds (open air factor=OAF) could be demonstrated on several days and quantitated in relative units of OAF concentration. In the absence of ozone the OAF concentration was...

Fotochemische smogvorming in Nederland (Photochemical smog formation in the Netherlands)

Characterization of the components of technically polychlorinated biphenyl mixtures-II

Safety evaluation of yeast grown on hydrocarbons. II: One-year feeding study in rats with yeast grown on pure n-paraffins

Yeast grown on hydrocarbons according to the n-paraffin process of The British Petroleum Company Ltd. was fed to groups of male and female rats at dietary levels of 10, 20 and 30% for 1 yr. Two control diets were used, one being similar to the yeast diet but with soya-bean meal substituted for yeast and the other being the institute's stock diet...

Safety evaluation of yeast grown on hydrocarbons. I: One-year feeding study in rats with yeast grown on gas oil

Yeast grown on hydrocarbons according to the gas-oil process was fed to rats at dietary levels of 10, 20 or 30% for 1 yr. Two control diets were used, one being similar to the yeast diets but containing soyabean-oil meal instead of yeast and the other being the institute's stock diet. The yeast diets had no effect on mortality, general condition...

Chlorinated biphenyls in fish, mussels and birds from the river rhine and the netherlands coastal area

Polychlorinated biphenyls are widely used in industry, and they are now making an appearance in the world's wildlife. Besides being a hazard in their own right, they interfere with the detection of organochlorine insecticides such as DDT. © 1969 Nature Publishing Group. Chemicals/CAS: liver extract, 72980-85-9; tissue extract, 1390-94-9, 8001-49...