Blanka Krauthacker

Levels of organochlorine pesticides and polychlorinated biphenyls (PCBs) in human milk and serum collected from lactating mothers in the northern adriatic area of Yugoslavia

Organochlorine pesticides and polychlorinated biphenyls (PCB) are persistent contaminants of the environment. Owing to their lipophilic properties they are primarily stored in fat-rich tissues and fluids of humans and animals. The results of a monitoring study on levels of the DDT-complex, HCH-group of isomers, hexachlorobenzene (HCB) and PCB in human milk and serum are presented in this paper. Samples were collected in the northern Adriatic area for which no data have so far been available. Sample donors were chosen from rural and small urban locations where mediterranean eating habits are still maintained. The previous studies were conducted in an industrialized continental town of Croatia.

Mechanism of inhibition in vitro of mammalian acetylcholinesterase and cholinesterase in solutions of O,O-dimethyl 2,2,2-trichloro-1-hydroxyethyl phosphonate (trichlorphon)

Abstract The rate of decomposition of trichlorphon into DDVP was measured polarographically at pH 7.4. The first order rate constants of decomposition at 25° are 7.27 × 10 −4 and 6.05 × 10 −4 min −1 for trichlorphon concentrations of 0.150 and 15.0 mM respectively; at 37° the corresponding rate constants are 53.1 × 10 −4 and 37.1 × 10 −4 min −1 . The rate of decomposition of trichlorphon was also calculated from the kinetics of inhibition of acetylcholinesterase (EC 3.1.1.7) and cholinesterase (EC 3.1.1.8) in trichlorphon solutions at 25° and 37° (pH 7.4). The following enzyme sources were used: bovine erythrocytes and rat brain acetylcholinesterase, and human, horse and rat plasma cholinesterase. The rate of decomposition of trichlorphon was calculated by assuming that only DDVP formed from trichlorphon is the enzyme inhibitor, while trichlorphon itself does not act as an inhibitor. The calculated rate constants for the decomposition of trichlorphon are lower or just within the range of the rate constants obtained by the polarographic method. This agreement was taken as kinetic evidence that trichlorphon is not an inhibitor of mammalian cholinesterases. The effect of pH on enzyme inhibition supports this conclusion. The rate of inhibition of bovine erythrocyte acetylcholinesterase by DDVP is the same at pH 7.4 and pH 6.0 (37°). However, the rate of enzyme inhibition in trichlorphon solutions is 30 times faster at pH 7.4 than at pH 6.0, and this agrees with the greater stability of trichlorphon at the lower pH value. The rate of spontaneous reactivation of the enzyme was measured (37°, pH 7.4) after inhibition in trichlorphon solutions of acetylcholinesterase (human and bovine erythrocytes) and cholinesterase (human plasma). For all three enzyme preparations, the rate of spontaneous reactivation was the same as that obtained after inhibition by DDVP. All results point to the conclusion that trichlorphon in vitro is not an inhibitor of mammalian cholinesterases.

Are Pine Needles Bioindicators of Air Pollution? Comparison of Organochlorine Compound Levels in Pine Needles and Ambient Air

Are Pine Needles Bioindicators of Air Pollution? Comparison of Organochlorine Compound Levels in Pine Needles and Ambient Air Levels of six PCB congeners and seven organochlorine pesticides were investigated and compared in ambient air and in pine needle samples. The applied methods are suitable for the analysis of PCBs and organochlorine pesticides in environmental samples and for their detection in recent intakes. DDE, HCB, lindane, PCB-28, PCB-52, PCB-101, PCB-138 and PCB-153 were found in all pine needle and air samples. The highest median values were found for PCB-28, PCB-101 and γ-HCH, and the lowest for PCB-180 and DDD. The median value of α-HCH/ γ-HCH ratios was 0.2 in both matrices. DDE/DDT ratios were close to or below 1 in some pine needle and ambient air samples. The results showed a correspondence between air and pine needle pollution; the same compounds were present in the highest or in the lowest levels in both types of matrices. These results suggest that pine needles are passive biomonitors of air pollution. Jesu Li Borove Iglice Bioindikatori Onečiščenja Zraka? Usporedba Razina Organoklorovih Spojeva u Borovim Iglicama i Zraku Ispitane su i uspoređene razine šest indikatorskih kongenera PCB-a i sedam organoklorovih pesticida u uzorcima zraka i borovih iglica. Primijenjene metode prikladne su za analizu PCB-a i organoklorovih pesticida u uzorcima iz okoliša te za određivanje njihova unosa u okoliš. DDE, HCB, lindan, PCB-28, PCB- 52, PCB-101, PCB-138 i PCB-153 nađeni su u svim uzorcima zraka i borovih iglica. PCB-28, PCB-101 i γ-HCH prisutni su u najvišoj, a PCB-180 i DDD u najnižoj razini. U obje matrice omjer α-HCH/γ-HCH je 0.2. Omjer DDE/DDT jednak je ili manji od jedinice u nekim uzorcima zraka i borovih iglica. Iz prikazanih rezultata vidljivo je da je onečišćenje zraka i borovih iglica slično, tj. da su isti spojevi prisutni u najvišim odnosno najnižim razinama u obje matrice. Rezultati upućuju na to da su vrste i razine organoklorovih spojeva u borovim iglicama dobar pokazatelj prosječnog profila onečišćenja zraka.

Organochlorine pesticides in blood serum of the general yugoslav population and in occupationally exposed workers

SummaryThe content of chlorinated hydrocarbon pesticide residues was determined by gas chromatography in serum samples of the general population living in four different parts of Yugoslavia and in two groups of occupationally exposed workers. The serum samples (193) were analyzed for p,p′-DDT, p,p′-DDE, p,p′-DDD, Lindane, and alpha-HCH. All samples contained p,p′-DDE. Few samples from the general population contained Lindane or alpha-HCH. Workers engaged in the production, formulation and packing of pesticides had a higher incidence and higher contents of the residues than the general population. The concentrations of residues in the general population fall within the ranges reported for other countries.

Cholinesterases in rabbit serum

1. Rabbit serum was shown to contain two cholinesterases which hydrolysed acetylthiocholine and butyrylthiocholine and one cholinesterase which hydrolysed only butyrylthiocholine. 2. The three enzymes were identified by the kinetics of heat inactivation and kinetics of phosphorylation by the organophosphate VX. 3. Using selective inhibitors (iso-OMPA, eserine, BNPP and BW-284C51) it was shown that the hydrolysis of acetylthiocholine and butyrylthiocholine in untreated native serum had properties of acetylcholinesterase (EC 3.1.1.7), butyrylcholinesterase (EC 3.1.1.8) and also some properties of carboxylesterase (EC 3.1.1.1). 4. Separation of proteins (on PAA-gels) in untreated native serum gave four bands with acetylthiocholine and three with butyrylthiocholine. 5. The two cholinesterases hydrolysing both substrates corresponded to the slow moving bands on the gel. 6. The fastest moving band hydrolysing only butyrylthiocholine could be attributed to the cholinesterase least sensitive to VX.

Exposure to organochlorine compounds of population groups in Croatia

Summarizes and discusses published data on the exposure to organochlorine pesticides (DDT, HCH isomers, HCB), polychlorinated biphenyls (PCB), polychlorinated dibenzo‐p‐dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). Presents the levels of organochlorine compounds found in human blood serum (general population and occupationally exposed subjects) and human milk. Also presents the calculated intake of organochlorine compounds by breast‐fed infants and their mothers. Observes no marked difference between levels of organochlorine compounds in population groups from Croatia and those reported from most European countries.