Distribution and ecological risk of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in surface sediments from the Bizerte lagoon,Tunisia

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 18 surface sediment samples collected from Bizerte lagoon, Tunisia. The total concentrations of ten PCBs (∑PCBs) and of four OCPs (∑OCPs) in the sediments from this area ranged from 0.8 to 14.6 ng g^?1 dw (average value, 3.9 ng g^?1 dw) and from 1.1 to 14.0 ng g^?1 dw (average value, 3.3 ng g^?1 dw), respectively. Among the OCPs, the range of concentrations of dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorobenzene (HCB) were 0.3–11.5 ng g^?1 dw (1.9 ng g^?1 dw) and 0.6–2.5 ng g^?1 dw (1.4 ng g^?1 dw), respectively. Compositional analyses of the POPs indicated that PCB 153, 138 and 180 were the predominant congeners accounting for 60 % of the total PCBs. In addition, p,p′-DDT was found to be the dominant DDTs, demonstrating recent inputs in the environment. Compared with some other regions of the world, the Bizerte lagoon exhibited low levels of PCBs and moderate levels of HCB and DDTs. The high ratios ΣPCBs/ΣDDTs indicated predominant industrial versus agricultural activities in this area. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs, as recorded at most of the study sites, was insignificant. However, the higher concentrations in stations S1 and S3 could cause biological damage.     

Academic expertise in assisting private companies in the fields of environment and environmental toxicology: the role of individual expertise

Environmental Science and Pollution Research - The scientific knowledge produced by academic research can be valued in all sectors of human activity, including private sector. The ROVALTAIN...     

First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands

Environmental Science and Pollution Research - Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the...     

Hg concentrations and stable isotope variations in tropical fish species of a gold-mining-impacted watershed in French Guiana

Environmental Science and Pollution Research - The aim of the study was to determine if gold-mining activities could impact the mercury (Hg) concentrations and isotopic signatures in freshwater...     

Removal efficiency of emerging micropollutants in biofilter wastewater treatment plants in tropical areas

Environmental Science and Pollution Research - We studied the removal of 61 emerging micropollutants, including illicit drugs, in a biofilter wastewater treatment plant located in the French Indies...     

The theory of planned behavior as mediator of the effect of parental supervision: a study of intentions to violate driving rules in a representative sample of adolescents

INTRODUCTION: The study reported here was designed to test the ability of the theory of planned behavior to mediate the effect of parental supervision on adolescents' intentions to violate driving rules. METHOD: A representative sample of 1,654 adolescents completed questionnaires during individual and anonymous interviews carried out at their schools. RESULTS: Results showed that age, gender, prior risky driving-behavior, and parental supervision significantly predict intentions to violate driving rules. Attitude and the subjective norm partially mediate the effect of age, prior behavior, and parental supervision. Perceived behavioral control does not predict intention and is not predicted by other variables. IMPACT: The results suggest that social cognitive variables partially mediate the effect of parenting practices such as supervision.     

Loss of legs: is it or not a handicap for an orb-weaving spider?

Leg loss is a common phenomenon in spiders, and according to the species 5% to 40% of the adults can present at least one missing leg. There is no possibility of regeneration after adult moult and the animal must manage with its missing appendages until its death. With the loss of one or more legs, female orb-weaving spiders can be penalized twice: firstly, because the legs are necessary for web construction and secondly, the legs are essential for the control of the prey after its interception by the web. During development, spiders may be also penalized because regeneration has energetic costs that take away resources for survival, growth and reproduction. All these consequences should influence negatively the development of the spider and thus its fitness. We investigated the impact of leg loss in the orb-weaving spider, Zygiella x-notata by studying its frequency in a natural population and web building and prey capture behaviours in laboratory. In field populations, 9.5% to 13%, of the adult females presented the loss of one or more legs; the majority of individuals had lost only one leg (in 48% of cases, a first one). Leg loss seems to affect all the adult spiders, as there is no difference of mass between intact spiders and those with missing leg. Data obtained with laboratory-reared spiders, showed that the loss of legs due to the moult is rare (less than 1%). Considering changes in web design, spiders with missing legs decreased their silk investment, increased the distance between spiral turns but did not change the capture surface of the web. Under our laboratory experimental conditions, spiders with one or two lost legs did not present any difference in prey capture efficiency. In laboratory conditions, spiders with lost leg(s) did not show any difference in egg sac production or in longevity (adult lifespan) compared to intact spiders.     

An individual and a sex odor signature in kittiwakes? Study of the semiochemical composition of preen secretion and preen down feathers

The importance of olfaction in birds’ social behavior has long been denied. Avian chemical signaling has thus been relatively unexplored. The black-legged kittiwake provides a particularly appropriate model for investigating this topic. Kittiwakes preferentially mate with genetically dissimilar individuals, but the cues used to assess genetic characteristics remain unknown. As in other vertebrates, their body odors may carry individual and sexual signatures thus potentially reliably signaling individual genetic makeup. Here, we test whether body odors in preen gland secretion and preen down feathers in kittiwakes may provide a sex and an individual signature. Using gas chromatography and mass spectrometry, we found that male and female odors differ quantitatively, suggesting that scent may be one of the multiple cues used by birds to discriminate between sexes. We further detected an individual signature in the volatile and nonvolatile fractions of preen secretion and preen down feathers. These results suggest that kittiwake body odor may function as a signal associated with mate recognition. It further suggests that preen odor might broadcast the genetic makeup of individuals, and could be used in mate choice to assess the genetic compatibility of potential mates.     

Genotoxicity associated with oxidative damage in the liver and kidney of mice exposed to dimethoate subchronic intoxication

Background and aims  

Because of the widespread use of pesticides for domestic and industrial applications, the evaluation of their toxic effects is of major concern to public health. The aim of the present study was to investigate the propensity of dimethoate (DM), an organophosphorus pesticide, to cause oxidative damage in the liver and kidney of mice and its associated genotoxic effect.