Rakesh Kumar Ghosh

Effect of organic manure on sorption and degradation of azoxystrobin in soil.

Information on pesticide degradation and factors influencing are important in predicting the levels of pesticide remaining in soils and allow assessment of potential risk associated with exposure. The present study reports the sorption and degradation of azoxystrobin [methyl (E)-2-{2-(6-(2-cyanophenoxy)pyrimidin-4-yloxy)phenyl}-3-methoxyacrylate] in a sandy loam soil. The fungicide was moderately sorbed, and the Freundlich adsorption parameter K(f) (1/n) values in natural and 5% compost-amended soils were 9.31 and 13.72, respectively. Sorption showed hysteresis with 32.5 and 14.7% of sorbed fungicide desorbed from the natural and 5% compost-amended soils, respectively. Azoxystrobin was more persistent in the aerobic soil than the anaerobic soil with half-life values of 107.47 and 62.69 days, respectively. Amendment of compost (5%) to the soil enhanced the degradation of fungicide, and the respective half-life values in aerobic and anaerobic soils were 73.39 and 38.58 days, respectively. Azoxystrobin acid was recovered as the only metabolite of azoxystrobin degradation in soils. Both sunlight and UV light affected the persistence of azoxystrobin with fungicide degraded at a faster rate in UV light than in sunlight. Soil acts as a screen and slows the fungicide degradation under sunlight and UV light.

Exposure to air pollution in critical prenatal time windows and IgE levels in newborns.

To cite this article: Herr CEW, Ghosh R, Dostal M, Skokanova V, Ashwood P, Lipsett M, Joad JP, Pinkerton KE, Yap P‐S, Frost JD, Sram R, Hertz‐Picciotto I. Exposure to air pollution in critical prenatal time windows and IgE levels in newborns. Pediatric Allergy Immunology 2011: 22: 75–84.

Air pollution exposure during critical time periods in gestation and alterations in cord blood lymphocyte distribution: a cohort of livebirths

BackgroundToxic exposures have been shown to influence maturation of the immune system during gestation. This study investigates the association between cord blood lymphocyte proportions and maternal exposure to air pollution during each gestational month.MethodsCord blood was analyzed using a FACSort flow cytometer to determine proportions of T lymphocytes (CD3+ cells and their subsets, CD4+ and CD8+), B lymphocytes (CD19+) and natural killer (NK) cells. Ambient air concentrations of 12 polycyclic aromatic hydrocarbons (PAH) and particulate matter < 2.5 micrometer in diameter (PM2.5) were measured using fixed site monitors. Arithmetic means of these pollutants, calculated for each gestational month, were used as exposure metrics. Data on covariates were obtained from medical records and questionnaires. Multivariable linear regression models were fitted to estimate associations between monthly PAH or PM2.5 and cord blood lymphocytes, adjusting for year of birth and district of residence and, in further models, gestational season and number of prior live births.ResultsThe adjusted models show significant associations between PAHs or PM2.5 during early gestation and increases in CD3+ and CD4+ lymphocytes percentages and decreases in CD19+ and NK cell percentages in cord blood. In contrast, exposures during late gestation were associated with decreases in CD3+ and CD4+ fractions and increases in CD19+ and NK cell fractions. There was no significant association between alterations in lymphocyte distribution and air pollution exposure during the mid gestation.ConclusionsPAHs and PM2.5 in ambient air may influence fetal immune development via shifts in cord blood lymphocytes distributions. Associations appear to differ by exposure in early versus late gestation.

No improvement in socioeconomic inequalities in birthweight and preterm birth over four decades: a population-based cohort study

BackgroundBirthweight and gestational age are associated with socioeconomic deprivation, but the evidence in relation to temporal changes in these associations is sparse. We investigated changes in the associations between socioeconomic status (SES) and birthweight and gestational age in Newcastle upon Tyne, North of England, during 1961–2000.MethodsWe used population-based data from hospital neonatal records on all singleton births to mothers resident in Newcastle (births with complete covariate information n = 113,182). We used linear regression to analyse the associations between neighbourhood SES and birthweight over the entire 40-year period and by decade, and logistic regression for associations with low birthweight (LBW) and preterm birth, adjusting for potential confounders.ResultsThere was a significant interaction between SES and decade of birth for birthweight (p = 0.028) and preterm birth (p < 0.001). Socioeconomic gradients were similar in each decade for birthweight outcomes, but for preterm birth, socioeconomic disparities were more evident in the later decades [for 1961–70, odds ratio (OR) was 1.1, 95% CI 0.9, 1.3, for the most deprived versus the least deprived quartile, while for 1991–2000, the corresponding OR was 1.5, 95% CI 1.3, 1.7]. In each decade, there was a significant decrease in birthweight adjusted for gestational age for the most deprived compared to the least deprived SES group [1961–1970: –113.4 g (95% CI–133.0, –93.8); 1991–2000: –97.5 g (95% CI–113.0, –82.0)], while there was a significant increase in birthweight in each SES group over time.ConclusionsSocioeconomic inequalities did not narrow over the four decades for birthweight and widened for preterm birth. Mean birthweight adjusted for gestational age increased in all socioeconomic groups, suggesting an overall increase in fetal growth.

Development of a hybrid proximal sensing method for rapid identification of petroleum contaminated soils.

UNLABELLED Using 108 petroleum contaminated soil samples, this pilot study proposed a new analytical approach of combining visible near-infrared diffuse reflectance spectroscopy (VisNIR DRS) and portable X-ray fluorescence spectrometry (PXRF) for rapid and improved quantification of soil petroleum contamination. Results indicated that an advanced fused model where VisNIR DRS spectra-based penalized spline regression (PSR) was used to predict total petroleum hydrocarbon followed by PXRF elemental data-based random forest regression was used to model the PSR residuals, it outperformed (R(2)=0.78, residual prediction deviation (RPD)=2.19) all other models tested, even producing better generalization than using VisNIR DRS alone (RPDs of 1.64, 1.86, and 1.96 for random forest, penalized spline regression, and partial least squares regression, respectively). Additionally, unsupervised principal component analysis using the PXRF+VisNIR DRS system qualitatively separated contaminated soils from control samples. CAPSULE Fusion of PXRF elemental data and VisNIR derivative spectra produced an optimized model for total petroleum hydrocarbon quantification in soils.

Leaching behaviour of azoxystrobin and metabolites in soil columns.

BACKGROUND Azoxystrobin [methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate], a strobilurin fungicide, is a broad-spectrum, systemic and soil-applied fungicide. Azoxystrobin has been registered for rice cultivation in India, but no information is available on its leaching behaviour in Indian soils. Therefore, leaching behaviour of azoxystrobin was studied in packed and intact soil columns under different irrigation regimes. RESULTS Azoxystrobin did not leach out of the 300 mm long columns after 126 and 362 mm rainfall. After percolating water equivalent to 362 mm rainfall, azoxystrobin leached down to 10-15 cm (packed columns) and 15-20 cm (intact columns) depth. Azoxystrobin was not detected in the leachate from the packed column leached with 94.5 mL water every week (140 mm rainfall per month) during the 28 weeks of the study period. However, azoxystrobin acid, formed by azoxystrobin degradation, was detected in the leachate after 18 weeks. At the end of the study, azoxystrobin had leached down to 5-10 cm depth, and only 60% of initially applied azoxystrobin was recovered from the soil. CONCLUSION The results indicate that azoxystrobin is fairly immobile in sandy loam soil, but azoxystrobin acid, a major metabolite of azoxystrobin, is quite mobile and may pose a threat of soil and groundwater contamination.

Indoor Coal Use and Early Childhood Growth

OBJECTIVE To examine whether indoor coal combustion for heating, which releases pollutants into the air, affects early childhood growth. DESIGN A prospective longitudinal study, with growth measurements extracted from medical records of the childrens well-child care visits at age 36 months. Data were compiled from self-administered questionnaires and medical records, both completed at 2 time points: delivery and follow-up. SETTING Teplice and Prachatice districts in the Czech Republic. PARTICIPANTS A total of 1133 children followed from birth to age 36 months. MAIN EXPOSURE Maternally reported use of coal for heating. MAIN OUTCOME MEASURE The z score for height for age and sex at age 36 months. RESULTS Adjusted for covariates, indoor coal use was significantly associated with a lower z score for height for age and sex at age 36 months (z score = -0.37; 95% confidence interval, -0.60 to -0.14). This finding translates into a reduction in height of about 1.34 cm (95% confidence interval, 0.51 to 2.16) for boys and 1.30 cm (95% confidence interval, 0.50 to 2.10) for girls raised in homes that used coal. The association between coal use and height was modified by postnatal cigarette smoke exposure. CONCLUSIONS Pollution from indoor coal use may impair early childhood skeletal growth to age 36 months. Because a significant proportion of the world population still uses coal indoors, the finding has public health consequences.

Optimization of a sample preparation method for multiresidue analysis of pesticides in tobacco by single and multi-dimensional gas chromatography-mass spectrometry

A selective and sensitive multiresidue analysis method, comprising 4 7pesticides, was developed and validated in tobacco matrix. The optimized sample preparation procedure in combination with gas chromatography mass spectrometry in selected-ion-monitoring (GC-MS/SIM) mode offered limits of detection (LOD) and quantification (LOQ) in the range of 3-5 and 7.5-15ng/g, respectively, with recoveries between 70 and 119% at 50-100ng/g fortifications. In comparison to the modified QuEChERS (Quick-Easy-Cheap-Effective-Rugged-Safe method: 2g tobacco+10ml water+10ml acetonitrile, 30min vortexing, followed by dispersive solid phase extraction cleanup), the method performed better in minimizing matrix co-extractives e.g. nicotine and megastigmatrienone. Ambiguity in analysis due to co-elution of target analytes (e.g. transfluthrin-heptachlor) and with matrix co-extractives (e.g. δ-HCH-neophytadiene, 2,4-DDE-linolenic acid) could be resolved by selective multi-dimensional (MD)GC heart-cuts. The method holds promise in routine analysis owing to noticeable efficiency of 27 samples/person/day.

Particulate matter exposure during pregnancy is associated with birth weight, but not gestational age, 1962-1992: a cohort study

BackgroundExposure to air pollutants is suggested to adversely affect fetal growth, but the evidence remains inconsistent in relation to specific outcomes and exposure windows.MethodsUsing birth records from the two major maternity hospitals in Newcastle upon Tyne in northern England between 1961 and 1992, we constructed a database of all births to mothers resident within the city. Weekly black smoke exposure levels from routine data recorded at 20 air pollution monitoring stations were obtained and individual exposures were estimated via a two-stage modeling strategy, incorporating temporally and spatially varying covariates. Regression analyses, including 88,679 births, assessed potential associations between exposure to black smoke and birth weight, gestational age and birth weight standardized for gestational age and sex.ResultsSignificant associations were seen between black smoke and both standardized and unstandardized birth weight, but not for gestational age when adjusted for potential confounders. Not all associations were linear. For an increase in whole pregnancy black smoke exposure, from the 1st (7.4 μg/m3) to the 25th (17.2 μg/m3), 50th (33.8 μg/m3), 75th (108.3 μg/m3), and 90th (180.8 μg/m3) percentiles, the adjusted estimated decreases in birth weight were 33 g (SE 1.05), 62 g (1.63), 98 g (2.26) and 109 g (2.44) respectively. A significant interaction was observed between socio-economic deprivation and black smoke on both standardized and unstandardized birth weight with increasing effects of black smoke in reducing birth weight seen with increasing socio-economic disadvantage.ConclusionsThe findings of this study progress the hypothesis that the association between black smoke and birth weight may be mediated through intrauterine growth restriction. The associations between black smoke and birth weight were of the same order of magnitude as those reported for passive smoking. These findings add to the growing evidence of the harmful effects of air pollution on birth outcomes.

Air pollution and childhood bronchitis: Interaction with xenobiotic, immune regulatory and DNA repair genes.

BACKGROUND Gene-environment interactions have been investigated for diseases such as asthma, chronic obstructive pulmonary disease, cancer etc. but acute disease like bronchitis has rarely been studied. We investigated interactions between air pollution (polycyclic aromatic hydrocarbons (PAH) and particulate matter <2.5 μm (PM2.5)) and single nucleotide polymorphisms (SNP) in EPHX1, IL10, STAT4 and XPC genes in relation to bronchitis in children aged 0-2 years. METHODS A stratified random sample of 1133 Czech children, born between 1994 and 1998 in two districts, were followed since birth, of which 626 were genotyped. Pediatrician-diagnosed bronchitis episodes were obtained from the medical records. Central-site monitors measured air pollution exposure. We used multivariable logistic regression and estimated coefficients using generalized estimating equations. Interaction was assessed between pollutants and genes and associations in genotype-specific strata were presented. False discovery rate was used to adjust for multiple comparisons. RESULTS There were 803 episodes of bronchitis with an incidence rate of 56 per 1000 child-months. We found significant gene-environment interaction between PAH and four SNPs (EPHX1, (rs2854461), STAT4 (rs16833215), XPC (rs2228001 and rs2733532)), which became non-significant after adjusting for multiple comparisons. PM2.5 interactions with two XPC SNPs (rs2228001 and rs2733532) remained significant after accounting for multiple comparisons and those with CC alleles had a more than doubling of odds, OR=2.65 (95% CI: 1.91, 3.69) and 2.72 (95% CI: 1.95, 3.78), respectively, per 25 μg/m(3) increase in exposure. CONCLUSION The findings suggest that the DNA repair gene XPC may play an important role in the air pollution-induced pathogenesis of the inflammatory disease bronchitis.