Genotoxic biomonitoring of agricultural workers exposed to pesticides in the north of Sinaloa State, Mexico

Genotoxic damage was evaluated in 70 agricultural workers, 25 women and 45 men, exposed to pesticides in Las Grullas, Ahome, Sinaloa, Mexico, with an average of 7 years of exposure. The effect was detected through the sister chromatid exchanges (SCE) in lymphocytes of peripheral blood and micronuclei (MN) and other nuclear anomalies (NA) in buccal exfoliated cells. Also, the influence on cellular proliferation kinetics (CPK) was studied by means of the replication index (RI) and the cytotoxic effect was examined with the mitotic index (MI). The non-exposed group consisted of 70 other persons, 21 women and 47 men from the city of Los Mochis, Sinaloa, Mexico. Significant differences between the exposed and the non-exposed groups were observed in SCE, CPK, MI, MN and NA. Analysis of variance revealed that age, gender, smoking and alcohol consumption did not have a significant effect on genetic damage. However, there was a correlation between exposure time to pesticides and SCE frequency. These results could have been due to the exposure of workers to pesticides containing different chemical compounds. This study afforded valuable data to estimate the possible risk to health associated with pesticide exposure.     

Factors influencing the food transition in riverine communities in the Brazilian Amazon

The objective of this study was to determine the main patterns and factors influencing food transition in riverine people in the Brazilian Amazon. Through interviews with a semi-structured questionnaire, we inferred their food habits and provide information about general demographic, socioeconomic, resource use and environmental context. Data from the questionnaires were categorized and analyzed using a logistic regression model to assess the relative influence of socioeconomic and environment factors on the local diet. Based on a logistic regression data analysis, it was found a greater consumption of processed food significantly associated with multiple factors such as market participation, sex (female and male), government aid to forest conservation and environment context (upland and wetland). Although the local diet is composed mainly of local resources such as fish and cassava flour, increasing incomes due to direct government subsidy programs and marketing of cassava flour have influenced these local practices and habits. Through the analysis of factors influencing food transition, it was possible to evaluate those having the greatest effect on this Amazon region and propose an alternative method to subsidy food policy grounded in local opinion surveys.     

Correlates of bushmeat in markets and depletion of wildlife

We used data on number of carcasses of wildlife species sold in 79 bushmeat markets in a region of Nigeria and Cameroon to assess whether species composition of a market could be explained by anthropogenic pressures and environmental variables around each market. More than 45 mammal species from 9 orders were traded across all markets; mostly ungulates and rodents. For each market, we determined median body mass, species diversity (game diversity), and taxa that were principal contributors to the total number of carcasses for sale (game dominance). Human population density in surrounding areas was significantly and negatively related to the percentage ungulates and primates sold in markets and significantly and positively related to the proportion of rodents. The proportion of carnivores sold was higher in markets with high human population densities. Proportion of small‐bodied mammals (<1 kg) sold in markets increased as human population density increased, but proportion of large‐bodied mammals (>10 kg) decreased as human population density increased. We calculated an index of game depletion (GDI) for each market from the sum of the total number of carcasses traded per annum and species, weighted by the intrinsic rate of natural increase (r_max) of each species, divided by individuals traded in a market. The GDI of a market increased as the proportion of fast‐reproducing species (highest r_max) increased and as the representation of species with lowest r_max (slow‐reproducing) decreased. The best explanatory factor for a market's GDI was anthropogenic pressure—road density, human settlements with >3000 inhabitants, and nonforest vegetation. High and low GDI were significantly differentiated by human density and human settlements with >3000 inhabitants. Our results provided empirical evidence that human activity is correlated with more depleted bushmeat faunas and can be used as a proxy to determine areas in need of conservation action.     

Occurrence of THMs and HAAs in experimental chlorinated waters of the Quebec City area (Canada)

Haloacetic acids (HAAs) and trihalomethanes (THMs) were generated in bench-scale chlorination experiments using treated waters (prior to final chlorination) of the three major drinking water utilities of the Quebec City area. The purpose was to investigate the formation and occurrence of these chlorination by-products (CBPs) on a seasonal basis. Data for HAAs, THMs and other physico-chemical parameters were produced through a six-month sampling program with variable conditions of water quality, water temperature, applied chlorine dose and reaction time. In waters from the three utilities, chloroform (THM specie), dichloroacetic and trichloroacetic acid (HAA species) were the most prevalent compounds due to the low concentrations of bromide in the utilities' raw waters. Significant differences in CBP occurrence were noted between the three utilities' chlorinated waters, mainly due to the type of disinfectant applied to raw water. The use of pre-ozonation, as opposed to pre-chlorination (or direct chlorination) in one of the utilities appears to be the major factor contributing to that utility's potential for compliance with current THM and future HAA standards. Seasonal variations in THMs and HAAs were mainly associated with variations in organic precursors and to changes in water temperature (two parameters which vary widely on a seasonal basis in surface waters of southern Quebec), with CBP occurrence at its highest in spring. Statistical correlations between HAAs and THMs were moderate and only temperature appeared to affect the preponderance of one CBP or the other. Finally, a regression analysis was carried out aimed at associating each CBP to water quality and the experimental parameters. Thanks to their predictive ability, multivariate models seem to be the tools with the best potential for decision-making purposes.     

Molecular phylogeny of the American <Emphasis Type="Italic">Callinectes</Emphasis> Stimpson, 1860 (Brachyura: Portunidae), based on two partial mitochondrial genes

The genus Callinectes encompasses 16 species of commercially important swimming crabs. Most (13) occur on the Pacific and Atlantic coasts of the Americas. We compare mtDNA regions corresponding to 964 basepairs of the large (16S) and small (12S) ribosomal subunits among American Callinectes in order to examine phylogenetic relationships. The status of Callinectes affinis Fausto-Filho and Callinectes maracaiboensis Taissoun is questioned, and C. maracaiboensis is concluded to be a junior synonym of Callinectes bocourti A. Milne-Edwards, from which it cannot be consistently distinguished. We find two major lineages, one of which includes C. affinis, C. bocourti, Callinectes rathbunae Contreras, Callinectes sapidus Rathbun, and Callinectes toxotes Ordway. A second lineage is comprised of Callinectes arcuatus Ordway, Callinectes bellicosus (Stimpson), Callinectes danae Smith, Callinectes exasperatus (Gerstaecker), Callinectes larvatus Ordway, Callinectes ornatus Ordway, and Callinectes similis Williams. Definition of these clades is supported by previously described morphological differences in the length of the gonopods and shared physioecological adaptations. A calibrated molecular clock is used to estimate divergence of the two lineages near 13 mybp. Our analyses suggest that C. ornatus is the closest relative of C. arcuatus, and that C. affinis is closest to C. bocourti.     

Biochemical composition and digestive enzyme activity in larvae and postlarvae ofPenaeus japonicus during herbivorous and carnivorous feeding

The growth, survival, digestive enzyme activity and biochemical composition ofPenaeus japonicus (Bate) larvae and postlarvae were measured under three feeding regimes. Larvae were reared through the protozoeal stages usingChaetoceros gracilis. From the first mysis stage, three feeding regimes were used; (A)C. gracilis plusArtemia sp. nauplii, (B)Artemia sp. nauplii alone or (C)C. gracilis alone. No significant difference was found in growth, survival, protein content or lipid content of postlarvae from the treatments receiving the single-feed type, despite the low protein (7%) and highly unsaturated fatty acid content of the alga. Growth of larvae receiving the mixed diet was significantly higher than in the other treatments. Trypsin activity was more strongly influenced than amylase activity by dietary treatment, and differences in the ratio of these enzymes between treatments suggest independent control of their secretion. Trypsin activity recorded in larvae feeding onC. gracilis was up to six time higher than in larvae feeding onArtemia sp. nauplii, apparently in response to the low protein content of the alga. Larvae receiving the mixed diet exhibited an intermediate level of trypsin activity; it is suggested that the ingestion of algae is necessary for optimal assimilation of the zooplankton component of the diet.     

An overview to CERSSO's self evaluation of the cost-benefit on the investment in occupational safety and health in the textile factories: "a step by step methodology"

INTRODUCTION: The Pan American Health Organization (PAHO) and CERSSO collaborated to develop a new Tool Kit (TK), which became available in May 2002. PAHO already had a TK in place, and CERSSO requested that one be developed for their needs. CERSSO wanted to enable managers and line workers in garment factories to self-diagnose plant and workstation hazards and to estimate the costs and benefits of investing in occupational safety and health (OSH) as a way to improve productivity and competitiveness. METHODS: For consistency, the collaborating organizations agreed to construct the TK according to PAHO's methodology. The instrument was developed to be comprehensive enough that any user can collect the data easily. It integrates epidemiologic, risk assessment, clinic, engineering, and accountability issues, organized to include step-by-step training in: (a) performing risk assessments in the workplaces (risk factors); (b) making cause-effect relationships; (c) improving decision making on OSH interventions; (d) doing calculations of direct and indirect costs and savings; and (e) doing calculation of the overall cost-benefit of OSH interventions. RESULTS AND CONCLUSIONS: Since July 2002, about 2,400 employees and officials from 736 garment factories, Ministries of Labor, Health, Social Security Institutes, and Technical Training Institutions of Central America and the Dominican Republic have used this instrument. Systematically, they have calculated a positive relationship of the investment (3 to 33 times). Employers are now aware of the financial rewards of investing in OSH. The TK is available in Spanish, Korean, and English. In July 2003, a software program in Spanish and English was developed (180 persons have been trained in the region), which requires less time to execute with better reliability.