Spatial variability in levels of benzene, formaldehyde, and total benzene, toluene, ethylbenzene and xylenes in New York City: a land-use regression study

Background Hazardous air pollutant exposures are common in urban areas contributing to increased risk of cancer and other adverse health outcomes. While recent analyses indicate that New York City residents experience significantly higher cancer risks attributable to hazardous air pollutant exposures than the United States as a whole, limited data exist to assess intra-urban variability in air toxics exposures. Methods To assess intra-urban spatial variability in exposures to common hazardous air pollutants, street-level air sampling for volatile organic compounds and aldehydes was conducted at 70 sites throughout New York City during the spring of 2011. Land-use regression models were developed using a subset of 59 sites and validated against the remaining 11 sites to describe the relationship between concentrations of benzene, total BTEX (benzene, toluene, ethylbenzene, xylenes) and formaldehyde to indicators of local sources, adjusting for temporal variation. Results Total BTEX levels exhibited the most spatial variability, followed by benzene and formaldehyde (coefficient of variation of temporally adjusted measurements of 0.57, 0.35, 0.22, respectively). Total roadway length within 100 m, traffic signal density within 400 m of monitoring sites, and an indicator of temporal variation explained 65% of the total variability in benzene while 70% of the total variability in BTEX was accounted for by traffic signal density within 450 m, density of permitted solvent-use industries within 500 m, and an indicator of temporal variation. Measures of temporal variation, traffic signal density within 400 m, road length within 100 m, and interior building area within 100 m (indicator of heating fuel combustion) predicted 83% of the total variability of formaldehyde. The models built with the modeling subset were found to predict concentrations well, predicting 62% to 68% of monitored values at validation sites. Conclusions Traffic and point source emissions cause substantial variation in street-level exposures to common toxic volatile organic compounds in New York City. Land-use regression models were successfully developed for benzene, formaldehyde, and total BTEX using spatial indicators of on-road vehicle emissions and emissions from stationary sources. These estimates will improve the understanding of health effects of individual pollutants in complex urban pollutant mixtures and inform local air quality improvement efforts that reduce disparities in exposure

An Overview of 9/11 Experiences and Respiratory and Mental Health Conditions among World Trade Center Health Registry Enrollees

http://deepblue.lib.umich.edu/bitstream/2027.42/61276/1/farfel m, digrande l, brackbill r, galea s, overview of 9-11 experiences and respiratory and mental haelth conditions.pd

Spatial and temporal estimation of air pollutants in New York City: exposure assignment for use in a birth outcomes study

BACKGROUND: Recent epidemiological studies have examined the associations between air pollution and birth outcomes. Regulatory air quality monitors often used in these studies, however, were spatially sparse and unable to capture relevant within-city variation in exposure during pregnancy. METHODS: This study developed two-week average exposure estimates for fine particles (PM(2.5)) and nitrogen dioxide (NO(2)) during pregnancy for 274,996 New York City births in 2008–2010. The two-week average exposures were constructed by first developing land use regression (LUR) models of spatial variation in annual average PM(2.5) and NO(2) data from 150 locations in the New York City Community Air Survey and emissions source data near monitors. The annual average concentrations from the spatial models were adjusted to account for city-wide temporal trends using time series derived from regulatory monitors. Models were developed using Year 1 data and validated using Year 2 data. Two-week average exposures were then estimated for three buffers of maternal address and were averaged into the last six weeks, the trimesters, and the entire period of gestation. We characterized temporal variation of exposure estimates, correlation between PM(2.5) and NO(2), and correlation of exposures across trimesters. RESULTS: The LUR models of average annual concentrations explained a substantial amount of the spatial variation (R(2) = 0.79 for PM(2.5) and 0.80 for NO(2)). In the validation, predictions of Year 2 two-week average concentrations showed strong agreement with measured concentrations (R(2) = 0.83 for PM(2.5) and 0.79 for NO(2)). PM(2.5) exhibited greater temporal variation than NO(2). The relative contribution of temporal vs. spatial variation in the estimated exposures varied by time window. The differing seasonal cycle of these pollutants (bi-annual for PM(2.5) and annual for NO(2)) resulted in different patterns of correlations in the estimated exposures across trimesters. The three levels of spatial buffer did not make a substantive difference in estimated exposures. CONCLUSIONS: The combination of spatially resolved monitoring data, LUR models and temporal adjustment using regulatory monitoring data yielded exposure estimates for PM(2.5) and NO(2) that performed well in validation tests. The interaction between seasonality of air pollution and exposure intervals during pregnancy needs to be considered in future studies

Intraurban Variation of Fine Particle Elemental Concentrations in New York City

Few past studies have collected and analyzed within-city variation of fine particulate matter (PM_2.5) elements. We developed land-use regression (LUR) models to characterize spatial variation of 15 PM_2.5 elements collected at 150 street-level locations in New York City during December 2008–November 2009: aluminum, bromine, calcium, copper, iron, potassium, manganese, sodium, nickel, lead, sulfur, silicon, titanium, vanadium, and zinc. Summer- and winter-only data available at 99 locations in the subsequent 3 years, up to November 2012, were analyzed to examine variation of LUR results across years. Spatial variation of each element was modeled in LUR including six major emission indicators: boilers burning residual oil; traffic density; industrial structures; construction/demolition (these four indicators in buffers of 50 to 1000 m), commercial cooking based on a dispersion model; and ship traffic based on inverse distance to navigation path weighted by associated port berth volume. All the elements except sodium were associated with at least one source, with <i>R</i>² ranging from 0.2 to 0.8. Strong source-element associations, persistent across years, were found for residual oil burning (nickel, zinc), near-road traffic (copper, iron, and titanium), and ship traffic (vanadium). These emission source indicators were also significant and consistent predictors of PM_2.5 concentrations across years

Effect of novel curcumin-encapsulated chitosan-bioglass drug on bone and skin repair after gamma radiation: experimental study on a Wistar rat model.

International audienceRadiation therapy contributes to a significant increase in bone osteoporosis and skin loss. Various natural health products might be beneficial to reduce bone and skin alterations. Curcumin (CUR) medicines derived from natural plants have played an important role in health care. This study aims at synthesizing and evaluating the performance therapy of CUR-encapsulated bioglass-chitosan (CUR-BG-CH). In vitro, the antioxidant assay was evaluated by using 1,1-diphenyl-2-picrylhydrazyl free-radical (DPPH) scavenging and the nitroblue tetrazolium reduction. The CUR-BG-CH antimicrobial effects were tested in liquid media. In vivo, after rat 60 Co γ-radiation, the tissue wound-healing process was studied by grafting CUR and CUR-BG-CH in femoral condyle and dorsal skin rat tissue. The antioxidant studies indicated that CUR-BG-CH quenches free radicals more efficiently than unmodified CUR and had effective DPPH (91%) and superoxide anion (51%) radical scavenging activities. The CUR-BG-CH biomaterial exhibited an important antimicrobial activity against Staphylococcus aureus. The histomorphometric parameters showed amelioration in CUR-BG-CH-treated rats. An improved mechanical property was noticed (33.16 ± 5.0 HV) when compared with that of unmodified CUR group (23.15 ± 4.9 HV). A significant decrease in tumour necrosis factor-α cytokine production was noted in the CUR-BG-CH rats (90 pg/ml) as compared with that of unmodified CUR group (240 pg/ml). The total amount of hydroxyproline was significantly enhanced (33.5%) in CUR-BG-CH group as compared with that of control. Our findings suggested that CUR-BG-CH might have promising potential applications for wound healing