Occurrence and fate of pesticides in the Argentine stretch of the Paraguay-Paraná basin.

The Argentine stretch of the del Plata basin crosses regions devoted to extensive and intensive agriculture mostly with chemical pest control. The utilization of pesticides in the region has increased 900% in the last two decades associated with the introduction of biotech crops and direct-seeding techniques. Our objective was to study the occurrence, concentration, and fate of pesticides in surface water and bottom sediments of the principal tributaries and main watercourse of the Paraguay-Paraná River. We sampled 22 sites in the distal positions of the main affluents and main watercourse of the Paraná and report here results from two monitoring campaigns (2010-2012). Surface water and bottom sediments were analyzed according to standardized methods by matrix-solid-phase dispersion and liquid-liquid extraction, respectively. Twenty-three pesticide compounds were analyzed by gas chromatography. The results from both campaigns indicated a generalized but variable distribution in the concentrations detected throughout the basin. The ranges of total measured pesticide concentrations in water and sediments were, respectively, 0.004-6.62 µg/l and 0.16-221.3 µg/kg dry weight. Endosulfans, cypermethrin, and chlorpyrifos were ubiquitous compounds in both environmental compartments and quantitatively the most relevant. All concentrations detected in water were over the recommended guidelines for the protection of aquatic biota. The partitioning indicated a higher affinity for the sediments. Agricultural activity is the source of pesticide-pollution loads, transported by tributaries that reach the main watercourse and alter the quality of the aquatic ecosystem.

Water quality of the main tributaries of the Paraná Basin: glyphosate and AMPA in surface water and bottom sediments.

The Paraná River, the sixth largest in the world, is the receptor of pollution loads from tributaries traversing urban and industrialized areas plus agricultural expanses, particularly so in the river's middle and lower reaches along the Argentine sector. In the present study, we analyzed and discussed the main water quality parameters, sediment compositions, and content of the herbicide glyphosate plus its metabolite aminomethylphosphonic acid (AMPA) in water and sediments. Samples were obtained from distal positions in the principal tributaries of the Paraná and the main watercourse during surveys conducted in 2011 and 2012 to monitor the basin. Only 15 % of the water samples contained detectable concentrations of glyphosate at an average concentration of 0.60 µg/L, while no detectable levels of AMPA were observed. The herbicide and metabolite were primarily present in sediments of the middle and lower stretch's tributaries, there occurring at a respective average of 37 and 17 % in samples. The mean detectable concentrations measured were 742 and 521 µg/kg at mean, maximum, and minimum glyphosate/AMPA ratios of 2.76, 7.80, and 0.06, respectively. The detection of both compounds was correlated with the presence of sulfides and copper in the sediment matrix.

The prevalence of socioeconomic and behavioral characteristics and their impact on very low birth weight in black and white infants in Georgia.

OBJECTIVES: We examined possible reasons for the disparity in the rate of very low birth weight (VLBW) delivery (<1500 g) in the United States between black women and white women. METHODS: Using data from a population-based, case-control study of very low birth weight infants, we compared the prevalence of sociodemographic and behavioral characteristics between black and white mothers of normal birth weight infants; the difference in these characteristics between case and control mothers; and, using logistic regression, calculated odds ratios for VLBW for black versus white infants, adjusting for these characteristics. RESULTS: Although black women were disadvantaged on every variable examined, they did not report more behavioral risk factors. Among white women, several traditional risk factors were associated with VLBW, while among black women, only marital status, cigarette smoking, and vitamin nonuse were associated with VLBW delivery. Controlling for the socioeconomic and behavioral factors reduced the odds ratio for VLBW delivery among black mothers from 3.7 to 3.3. CONCLUSIONS: Racial disparity in socioeconomic status may be greater than our current ability to adjust for it in epidemiologic studies. The fact that traditional risk factors were not associated with VLBW delivery in black women may be due to the very high prevalence of these risk factors among black women or to different or additional risks or stresses experienced by black women.

Lack of definitive severe mitochondrial signs and symptoms among deceased HIV-uninfected and HIV-indeterminate children < or = 5 years of age, Pediatric Spectrum of HIV Disease project (PSD), USA.

BACKGROUND: In response to recent reports of mitochondrial dysfunction in HIV-uninfected infants exposed to antiretroviral (ARV) prophylaxis, the Perinatal Safety Review Working Group reviewed deaths in five large HIV-exposed perinatal cohorts in the United States to determine if similar cases of severe mitochondrial toxicity could be detected. We describe the results of this review for the PSD cohort. METHODS: Hospitalization, clinic and death records for deceased HIV-uninfected and HIV-indeterminate children who were less than 5 years of age were reviewed. Standard definitions were used to classify HIV infection status and the likelihood that signs and symptoms were related to mitochondrial dysfunction. Children were classified as having signs and symptoms that were considered (1) unrelated, (2) unlikely, (3) consistent with, or (4) likely related to mitochondrial disease. SIDS deaths were put into a separate category. RESULTS: 8,465 of 13,125 HIV-exposed children were either HIV-uninfected or HIV-indeterminate. Among the 84 deaths in the subgroup of 8,465 children, 9 were considered in Class 2 (unlikely), 4 were considered in Class 3 (consistent with), and none were considered in Class 4 (likely). 97% of those children who received ARV prophylaxis received zidovudine alone. None of the HIV-uninfected deaths were classified in 2, 3, or 4; and only one of these was exposed to ARV prophylaxis. Among the 3 HIV-indeterminate children who were classified in 3 (consistent with), 2 had no or unknown ARV exposure before 1994 when use of ZDV prophylaxis became the standard of care. Both HIV-uninfected and HIV-indeterminate children with ARV exposure or unknown exposure had lower mortality rates than children without ARV exposure. CONCLUSION: Monoprophylaxis with ZDV was not associated with higher death rates in the cohort of 8,465 children or with any findings likely consistent with mitochondrial dysfunction among the 85 deaths. Ongoing monitoring of drug safety in large multi-site prospective cohort studies of HIV-exposed children is essential in the era of highly active antiretroviral therapy.

Gestational age and intrauterine growth retardation among white and black very low birthweight infants: a population-based cohort study.

Very low birthweight (VLBW) is a commonly used endpoint in perinatal epidemiology, but the population of VLBW infants comprises a wide range of gestational ages and rates of fetal growth. We used data from a population-based study of all 1072 black and white VLBW liveborn infants born in 29 counties in Georgia between April 1986 and March 1988. Less than 1% of the VLBW infants were > or = 37 weeks gestation; most were 29-32 weeks (26%) or 25 to 28 weeks (40%); 12% were 22 weeks or less. All infants 33 weeks gestation or greater were growth retarded. The population of VLBW infants seems to comprise three groups: approximately 11% very immature infants of 22 weeks or less; the majority of infants, born between 23 and 30 weeks, 90% of which are of normal weight for their gestational age; and a group of less premature, growth-retarded infants from 31 to 36 weeks. We found little or no difference in the distribution of gestational age or the percentage of intrauterine growth rates (IUGR) between black and white infants. In the USA the VLBW rate among black infants is over three times greater than that among white infants and consequently the rates of the three types of VLBW among black infants are likely to be triple those among white infants.

Maternal thyroid disease and risk of birth defects in offspring: a population-based case-control study.

We investigated the relationship between maternal thyroid disease and the risk of birth defects in offspring using data from a large population-based, case-control study. Cases included 4904 stillborn and liveborn infants with major anomalies diagnosed in the first year of life and born to residents of metropolitan Atlanta between 1968 and 1980. Controls included 3027 normal babies, frequency-matched to cases by race, hospital of birth and quarter of birth. We compared mothers of cases and controls regarding history of physician-diagnosed hypothyroidism and hyperthyroidism before the infant's birth, age at diagnosis of thyroid condition, duration of illness, and intake of thyroid medications before and during pregnancy. Information obtained from maternal interviews was evaluated for concordance with hospital records. We adjusted for potentially confounding factors using conditional logistic regression analysis. Overall, there was no relationship between the risk of total birth defects and history of maternal hypothyroidism (odds ratio (OR) = 1.05, 95% C.I. 0.84-1.31), maternal hyperthyroidism (OR = 1.00, 95% C.I. 0.66-1.53), and intake of thyroid hormone and antithyroid drugs before and during pregnancy. In an analysis of 66 specific birth defects and defect groups, we found two statistically significant associations with hypothyroidism and three with hyperthyroidism which may reflect chance findings. In an evaluation of babies with multiple anomalies, we observed a two-fold increased risk with hypothyroidism but no discernible pattern of defects. The absolute risk of major birth defects in offspring of women with history of hypothyroidism can be estimated as 2.1%, a finding at odds with the 10-20% risk cited in the literature.