18 research outputs found
A Case for Revisiting the Safety of Pesticides: A Closer Look at Neurodevelopment
The quality and quantity of the data about the risk posed to humans by individual pesticides vary considerably. Unlike obvious birth defects, most developmental effects cannot be seen at birth or even later in life. Instead, brain and nervous system disturbances are expressed in terms of how an individual behaves and functions, which can vary considerably from birth through adulthood. In this article I challenge the protective value of current pesticide risk assessment strategies in light of the vast numbers of pesticides on the market and the vast number of possible target tissues and end points that often differ depending upon timing of exposure. Using the insecticide chlorpyrifos as a model, I reinforce the need for a new approach to determine the safety of all pesticide classes. Because of the uncertainty that will continue to exist about the safety of pesticides, it is apparent that a new regulatory approach to protect human health is needed
Association of maternal serum concentrations of 2,2', 4,4'5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) levels with birth weight, gestational age and preterm births in Inuit and European populations
<p>Abstract</p> <p>Background</p> <p>Epidemiological studies on the association between maternal exposure to persistent organic pollutants (POPs) and fetal growth alteration report inconsistent findings which weights in favor of additional studies.</p> <p>Methods</p> <p>Blood samples were collected from interviewed pregnant women in Greenland (572), Kharkiv (611) and Warsaw (258) and were analyzed for CB-153 and p,p'-DDE by gas chromatography-mass spectrometry. Data on birth weight, gestational age and preterm birth were obtained for 1322 singleton live births. We examined the association between natural log-transformed serum POPs concentration and birth weight and gestational age using multiple linear regression and the association with prematurity using logistic regression controlling for potential confounding factors.</p> <p>Results</p> <p>The median serum concentrations of CB-153 and p,p'-DDE were for Inuit mothers 105.6 and 298.9, for Kharkiv mothers 27.0 and 645.4 and for Warsaw mothers 10.7 and 365.2 ng/g lipids, respectively. Increase in CB-153 concentration by one unit on the log scale in Inuit mothers serum was associated with significant decrease in infant birth weight of -59 g and gestational age by -0.2 week. Decreases observed in the cohorts in Kharkiv (-10 g and -0.1 week) and in Warsaw (-49 g and -0.2 week) were not statistically significant. Increase in p,p'-DDE concentration by one unit on the log scale was associated with a statistically significant decrease in infant birth weight of -39.4 g and -104.3 g and shortening of gestational age of -0.2 week and -0.6 week in the Inuit and Warsaw cohorts, respectively. In the Kharkiv cohort decrease in birth weight (-30.5 g) was not significant, however a shortening of gestational age of -0.2 week per increase in p,p'-DDE concentration by one unit on the log scale was of the borderline significance. There was no significant association between CB-153 and p,p'-DDE concentrations and risk of preterm birth however, in all cohorts the odds ratio was above 1.</p> <p>Conclusions</p> <p><it>In utero </it>exposure to POPs may reduce birth weight and gestational age of newborns however, new insights as to why results vary across studies were not apparent.</p
Biochemical alterations induced by a new phosphorothionate (RPR-II) in tissues of male and female rats*
546-552This study
was conducted to investigate the effect of a new phosphorothionate, the methyl
ester of 2- butenoic acid-3-diethoxy phosphinothioyl (RPR-II) on membrane bound
target enzymes aspartate amino transferase (ASAT), alanine amino transferase
(ALAT) and RBC acetylcholinesterase (AChE) in different tissues of male and female
albino wistar rats when treated orally with 0.014 (low), 0.028 (medium) and 0.042
(high) mg/kg daily for a period of 90 days. Repeated administration of RPR-II caused
significant increase of ASAT
and ALAT enzymes
in serum, liver and kidney and significant decrease was recorded in lung in
both male and female rats when measured after 45 and 90 days of treatment. This
compound also caused significant inhibition of RBC AChE indicating its effect
on nerve synapsis. Females were more susceptible than males with regard to ASAT
and ALAT levels in serum and liver and also in kidney ASAT, whereas reverse
trend was recorded in lung ALAT, suggesting sexual dimorphism in the treated rats.
These studies also indicated that the levels of these affected enzymes were
recovered to normal conditions after 28 days of post treatment (withdrawal
study). Positive correlation was observed with regard to these enzymes between
serum, liver and kidney, whereas in case of serum and lung a negative
correlation was recorded. These enzymes profile elucidates lung necrosis whereas
in -other tissues the level of enzymes increased showing an adaptive mechanism
due to the chemical stress