Trace elements in blood of sea turtles Lepidochelys olivacea in the Gulf of California, Mexico.

This study determined the concentrations of heavy metals in blood collected from Pacific Ridley sea turtles (Lepidochelys olivacea) inhabiting the coast of Guasave, Mexico, in the Gulf of California. The highest reported metal concentration in blood was Zn, followed by Se. Of nonessential toxic metals, As was reported in higher percentage compared to Cd. The concentrations of metals detected were present as follows: Zn > Se > Mn > As > Ni > Cd > Cu. Cd concentration in blood is higher in our population in comparison with other populations of L. olivacea, and even higher in other species of sea turtles. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements, and is easily accessible and nonlethal for sea turtles.

Selected heavy metals and selenium in the blood of black sea turtle (Chelonia mydas agasiizzi) from Sonora, Mexico.

The concentration of heavy metals (Zn, Cd, Ni, Cu, Mn) and selenium (Se) was analyzed in blood collected from 12 black turtles (Chelonia mydas agasiizzi) captured in Canal del Infiernillo, Punta Chueca, Mexico. The most abundant metals were Zn (63.58 µg g(-1)) and Se (7.66 µg g(-1)), and Cd was the lower (0.99 µg g(-1)). The sequential concentrations of trace metals were Zn > Se > Cu > Mn > Ni > Cd. In conclusion, this information is important as a baseline when using blood as tissue analysis of heavy metals; however, these levels could represent recent exposure in foraging grounds of black turtles in the Sea of Cortez.

Abundancia y distribución de Aedes aegypti (Diptera: Culicidae) y dispersión del dengue en Guasave Sinaloa, México

Abundance and distribution of Aedes aegypti (Diptera: Culicidae), and dengue dispersion in Guasave Sinaloa, México. Dengue is an important disease that affects humans, and is transmitted by A. aegypti. During 2006, a total of 477 cases of hemorrhagic dengue, and 1 510 of classic dengue were recorded in Sinaloa. Due to this high impact, a study on insect abundance and distribution, as well as their relationship with dengue dispersion, was carried out from April 2008 to March 2009 in Guasave, Sinaloa. The study included a total of six sectors in the city, considering 16 colonies; besides, 96 traps were distributed in these sectors to monitor the vector population density and female number per trap. The adult density index (ADI) and traps positive index (TPI) were calculated, and data were used to obtain the monthly dengue dispersion maps. The highest abundance of female (137 and 139) was found in July and August. In August and September the sectors 2, 4 and 6 showed the highest ADI values 2.44, 3.35 and 2.290, while TPI values were 56.25, 58.82 and 61.54, with the highest epidemiology dengue dispersion. The Pearson correlation (p<0.05) showed better values with the precipitation (r=0.80) than mean temperature (r=0.76) with zero lag months; while the cases of classic dengue and hemorrhagic dengue (CD/HD) is mostly related with the precipitation (r=0.98), and minimum temperature (r=0.79), with two lag months. In conclusion, the ADI and TPI index, as well as the maps obtained, allowed us to know the location of epidemiologic dengue risk areas. This information can be used to develop better control measures biological and chemical for the mosquito, in this location. Rev. Biol. Trop. 59 (4): 1609-1619. Epub 2011 December 01.

El dengue es una enfermedad viral en humanos transmitida por el mosquito A. aegypti (L), principal vector en América. En el 2006 en Sinaloa México se presentaron 477 casos de dengue hemorrágico y 1 510 de dengue clásico, el estado presentó el mayor número de casos de dengue hemorrágico del país, debido a esto se realizó un estudio sobre la abundancia y distribución del mosquito de abril 2008 a agosto 2009 en Guasave Sinaloa, México. La Ciudad se dividió en seis sectores, en la cual se consideraron 16 colonias con el mayor número de casas por sector; se colocaron 96 trampas para monitorear la densidad de población del insecto y el número de hembras por trampa, esto datos sirvieron para calcular los índices de densidad de adultos (IDA) e índice de trampas positivas (ITP) por sector, los cuales junto con los casos de dengue permitieron elaboraron mapas de dispersión de la enfermedad. En julio y agosto se registró la abundancia más alta de hembras (137 y 139). En agosto y septiembre los sectores dos, cuatro y seis presentaron valores de IDA de 2.44, 3.35 y 2.29, por lo que fueron de un alto riesgo epidemiológico, mientras que en estos mismos sectores se encontraron los valores más altos de ITP (56.25, 58.82 y 61.54). Los valores de mayor asociación de las correlaciones entre la abundancia poblacional de hembras se obtuvo con la precipitación (r=0.80) y con la temperatura promedio (r=0.76), a cero meses de retraso. La correlación entre el DC/DH con la precipitación fue más alta (r=0.98) que con la temperatura mínima (r=0.79); ambas con dos meses de retraso. En este estudio se demostró que los mapas mensuales de dispersión epidemiológica sirven como una medida del riesgo de la enfermedad en Guasave, Sinaloa.

Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico.

Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 µg g⁻¹), followed by Selenium (10.92 µg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 µg g⁻¹ and 1.01µg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.

The NIOSH Retrospective Pesticide Reference Database.

For the National Institute for Occupational Safety and Health (NIOSH) case-control study of glioma among non-metropolitan residents, pesticide information was considered critical. Responses to open-ended questions about pesticide exposures had to be grouped for analysis. Our aim was to classify pesticide responses in biologically relevant categories. We built the NIOSH Retrospective Pesticide Reference Database (NIOSH-RPRD) on over 1000 pesticide products and chemicals, particularly those likely to be used in the upper Midwest, using multiple sources. We obtained first and last years of product registration and product pesticide ingredients and their relative weights from the U.S. Environmental Protection Agency's Pesticide Product Information System. We added fields for pesticide class (organophosphate, etc.), carcinogenicity ratings, and evidence regarding endocrine-disrupting activity. Participant data were merged with the database, allowing each product recalled by a respondent to be linked to one or more chemicals, as appropriate. Respondents named 1347 different pesticides (or pesticide-targeted species) used on the farm, at non-farm jobs, or at home. Database usefulness was assessed by comparing numbers of responses naming actual chemicals to total responses linked to those chemicals. Sixty percent of farm pesticide, 59% of non-farm occupational, and 65% of house and garden responses named products, not chemicals. Among farm pesticide users, 182 (46%) reported using a total of 440 pesticides 1 to 40 years (mean 8.5 years) before those pesticides actually were marketed. The NIOSH-RPRD, now available to other investigators, has been a useful tool for us and other researchers to evaluate, group, and correct pesticide responses.

The Upper Midwest Health Study: a case-control study of primary intracranial gliomas in farm and rural residents.

Since several studies indicated that farmers and agricultural workers had an excess risk of brain cancer, the National Institute for Occupational Safety and Health initiated the Upper Midwest Health Study to examine risk of intracranial glioma in the non-metropolitan population. This population-based, case-control study evaluated associations between gliomas and rural and farm exposures among adults (ages 18 to 80) in four upper midwestern states (Iowa, Michigan, Minnesota, Wisconsin). At diagnosis/selection, participants lived in non-metropolitan counties where the largest population center had fewer than 250,000 residents. Cases were diagnosed 1 January 1995 through 31 January 1997. Over 90% of 873 eligible ascertained cases and over 70% of 1670 eligible controls consented to participate. Participants and nonparticipants, evaluated for "critical questions" on main and refusant questionnaires, differed significantly in farming and occupational experience, ethnicity, education, and lifestyle. The 1,175 controls were more likely than the 798 cases to have reported ever drinking alcohol (77% vs. 73%, adjusted odds ratio (OR) 0. 73, 95% confidence interval (CI) 0.59-0.92) and having had panoramic dental x-rays (34% vs. 29%, OR 0. 75, CI 0.61-0.92). Controls spent a greater percentage of their lives in non-metropolitan counties (78% vs. 75%, OR 0.81, CI 0.67-1.09). Among ever-farmers, controls were more likely to have had exposure to farm insecticides (57% vs. 50%, OR 0.75, CI 0.59-0.95) and farm animals (96% vs. 91%, OR 0.48, CI 0.25-0.90). Moving to a farm as an adolescent (ages 11 to 20) vs. as an adult was associated with a greater risk of glioma. In our study sample, farm or rural residence and summary farm exposures were associated with decreased glioma risk. However, nonparticipation by never-farming eligible controls could have affected results. Comparisons of farm chemical exposures may clarify associations between farming and glioma that others have reported.

Environmental urban lead exposure and blood lead levels in children of Mexico City.

Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.