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1.
Int Arch Occup Environ Health ; 96(6): 919-930, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37225876

RESUMEN

PURPOSE: The Keokuk County Rural Health Study (KCRHS) is a longitudinal population-based study conducted in rural Iowa. A prior analysis of enrollment data identified an association of airflow obstruction with occupational exposures only among cigarette smokers. The current study used spirometry data from all three rounds to investigate whether level of forced expiratory volume in one second (FEV1) and longitudinal change in FEV1 were associated with occupational vapor-gas, dust, and fumes (VGDF) exposures, and whether these associations were modified by smoking. METHODS: This study sample comprised 1071 adult KCRHS participants with longitudinal data. A job-exposure matrix (JEM) was applied to participants' lifetime work histories to assign exposures to occupational VGDF. Mixed regression models of pre-bronchodilator FEV1 (millimeters, ml) were fit to test for associations with occupational exposures while adjusting for potential confounders. RESULTS: Mineral dust had the most consistent association with change in FEV1, including ever/never ( - 6.3 ml/year) and nearly every level of duration, intensity, and cumulative exposure. Because 92% of participants with mineral dust also had organic dust exposure, the results for mineral dust may be due to a combination of the two. An association of FEV1 level with fumes was observed for high intensity ( - 91.4 ml) among all participants, and limited to cigarette smokers with results of - 104.6 ml ever/never exposed, - 170.3 ml high duration, and - 172.4 ml high cumulative. CONCLUSION: The current findings suggest that mineral dust, possibly in combination with organic dust, and fumes exposure, especially among cigarette smokers, were risk factors for adverse FEV1 results.


Asunto(s)
Enfermedades Profesionales , Exposición Profesional , Enfermedad Pulmonar Obstructiva Crónica , Adulto , Humanos , Estudios Longitudinales , Volumen Espiratorio Forzado , Iowa/epidemiología , Población Rural , Exposición Profesional/efectos adversos , Polvo/análisis
2.
Int Arch Occup Environ Health ; 95(8): 1741-1754, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35482110

RESUMEN

OBJECTIVE: Farmers have an increased risk for chronic bronchitis and airflow obstruction. The objective of this study was to investigate the association of these health outcomes with farm activities. METHODS: We evaluated the Keokuk County Rural Health Study (KCRHS) enrollment data for farm activities and the two health outcomes chronic bronchitis based on self-reported symptoms and airflow obstruction based on spirometry. We used logistic regression to model the health outcomes, yielding an odds ratio (OR) and 95% confidence interval (95% CI) for farm activities while adjusting for potential confounders and other risk factors. RESULTS: Of the 1234 farmers, 104 (8.4%) had chronic bronchitis, 75 (6.1%) fulfilled the criteria for airflow obstruction, and the two outcomes overlapped by 18 participants. Chronic bronchitis without airflow obstruction (n = 86) had a statistically significant association with crop storage insecticides (OR 3.1, 95% CI 1.6, 6.1) and a low number of years (≤ 3) worked with turkeys (OR 3.3, 95% CI 1.2, 9.4). The latter result should be interpreted with caution because it is based on a small number of cases (n = 5). Airflow obstruction with or without chronic bronchitis (n = 75) was significantly associated with ever working in a hog or chicken confinement setting (OR 2.2, 95% CI 1.0, 4.5). CONCLUSIONS: These results suggest that work with crop storage insecticides or turkeys may increase the risk for chronic bronchitis and work in hog or chicken confinement may increase the risk for airflow obstruction.


Asunto(s)
Bronquitis Crónica , Insecticidas , Enfermedad Pulmonar Obstructiva Crónica , Bronquitis Crónica/epidemiología , Granjas , Volumen Espiratorio Forzado , Humanos , Iowa/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/epidemiología
3.
Environ Sci Technol ; 55(8): 4483-4493, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33715364

RESUMEN

The residential sector is a major source of air pollutant emission inventory uncertainties. A nationwide field emission measurement campaign was conducted in rural China to evaluate the variabilities of realistic emission factors (EFs) from indoor solid fuel combustion. For a total of 1313 burning events, the overall average EFs (±standard deviation) of PM2.5 were 8.93 ± 6.95 and 7.33 ± 9.01 g/kg for biomass and coals, respectively, and 89.3 ± 51.2 and 114 ± 87 g/kg for CO. Higher EFs were found from burning of uncompressed straws, while lower EFs were found from processed biomass pellets, coal briquettes, and relatively clean anthracite coals. Modified combustion efficiency was found to be the most significant factor associated with variations in CO EFs, whereas for PM2.5, fuel and stove differences determined its variations. Weak correlations between PM2.5 and CO indicated high uncertainties in using CO as a surrogate for PM2.5. EFs accurately fit log-normal distributions, and obvious spatial heterogeneity was observed attributed to different fuel-stove combinations across the country. Emission estimation variabilities, which are determined by the interquartile ranges divided by the median values, were notably reduced when spatially resolved EFs were adopted in the inventory.


Asunto(s)
Contaminantes Atmosféricos , Artículos Domésticos , Contaminantes Atmosféricos/análisis , Biomasa , China , Carbón Mineral/análisis , Material Particulado/análisis
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(11): 1075-1079, 2021 Nov 15.
Artículo en Inglés, Zh | MEDLINE | ID: mdl-34753537

RESUMEN

Congenital hypothyroidism is one of the common diseases causing delayed intelligence development and growth retardation in children. In 2021, the ENDO-European Reference Network updated the practice guidelines for the diagnosis and management of congenital hypothyroidism. The guidelines give a comprehensive and detailed description of the screening, diagnosis, and management of congenital hypothyroidism in neonates. This article gives an interpretation of the guidelines in order to provide a reference for clinicians in China.


Asunto(s)
Hipotiroidismo Congénito , Niño , China , Hipotiroidismo Congénito/diagnóstico , Consenso , Humanos , Recién Nacido , Tamizaje Neonatal , Tirotropina
5.
Am J Ind Med ; 63(5): 417-428, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32154609

RESUMEN

BACKGROUND: Asthma-related health outcomes are known to be associated with indoor moisture and renovations. The objective of this study was to estimate the frequency of these indoor environmental quality (IEQ) factors in healthcare facilities and their association with asthma-related outcomes among workers. METHODS: New York City healthcare workers (n = 2030) were surveyed regarding asthma-related symptoms, and moisture and renovation factors at work and at home during the last 12 months. Questions for workplace moisture addressed water damage (WD), mold growth (MG), and mold odor (MO), while for renovations they addressed painting (P), floor renovations (FR), and wall renovations (WR). Regression models were fit to examine associations between work and home IEQ factors and multiple asthma-related outcomes. RESULTS: Reports of any moisture (n = 728, 36%) and renovations (n = 1412, 70%) at work were common. Workplace risk factors for asthma-related outcomes included the moisture categories of WD by itself, WD with MO (without MG), and WD with MG and MO, and the renovation category with the three factors P, FR, and WR. Reports of home IEQ factors were less frequent and less likely to be associated with health outcomes. Data analyses suggested that MG and/or MO at work and at home had a synergistic effect on the additive scale with a symptom-based algorithm for bronchial hyperresponsiveness. CONCLUSIONS: The current study determined that moisture and renovation factors are common in healthcare facilities, potentially putting workers at risk for asthma-related outcomes. More research is needed to confirm these results, especially prospective studies.


Asunto(s)
Contaminación del Aire Interior/análisis , Asma Ocupacional/etiología , Personal de Salud/estadística & datos numéricos , Exposición Profesional/análisis , Lugar de Trabajo/estadística & datos numéricos , Adulto , Contaminación del Aire Interior/efectos adversos , Femenino , Arquitectura y Construcción de Hospitales/estadística & datos numéricos , Humanos , Humedad/efectos adversos , Masculino , Persona de Mediana Edad , Ciudad de Nueva York , Exposición Profesional/efectos adversos , Análisis de Regresión , Factores de Riesgo
6.
Chaos ; 30(10): 103101, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33138465

RESUMEN

Recent research has revealed that a system of coupled units with a certain degree of parameter diversity can generate an enhanced response to a subthreshold signal compared to that without diversity, exhibiting a diversity-induced resonance. We here show that diversity-induced resonance can also respond to a suprathreshold signal in a system of globally coupled bistable oscillators or excitable neurons, when the signal amplitude is in an optimal range close to the threshold amplitude. We find that such diversity-induced resonance for optimally suprathreshold signals is sensitive to the signal period for the system of coupled excitable neurons, but not for the coupled bistable oscillators. Moreover, we show that the resonance phenomenon is robust to the system size. Furthermore, we find that intermediate degrees of parameter diversity and coupling strength jointly modulate either the waveform or the period of collective activity of the system, giving rise to the resonance for optimally suprathreshold signals. Finally, with low-dimensional reduced models, we explain the underlying mechanism of the observed resonance. Our results extend the scope of the diversity-induced resonance effect.


Asunto(s)
Modelos Neurológicos , Neuronas , Vibración , Potenciales de Acción , Simulación por Computador
7.
J Environ Sci (China) ; 69: 155-165, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29941251

RESUMEN

As an effective pollution control method, emission allowance and allocation just implemented in volatile organic compounds (VOCs) control strategy of China in 2016. This article presents a possible way to set the emission allowance targets and establishes an allowance allocation model for the object year, 2020 and 2030, using 2010 as the reference year. On the basis of regression and scenario analysis method, the emission allowance targets were designed, which were 17.902Tg and 18.224Tg for 2020 and 2030, with an increasing rate of 28.75% and 31.06% compared to 2010. From the perspective of industries, processes using VOCs-containing products, like machinery and equipment manufacturing, would continue to be the most significant industrial VOCs emission sources in the future of China. Four allocation indicators were selected, which are per capita GDP of each province, per capita industrial VOCs emission of each province, the economic contribution of industrial sector to regional economy of each province, and the emission intensity per land area of each province, respectively. Based on information entropy, the weights of the indicators were calculated and an emission allocation model was established, and the results showed that provinces like Shandong, Jiangsu, Guangdong, Zhejiang and Fujian were calculated to obtain more emission allowance while burden more reduction responsibility. Meanwhile, provinces like Guizhou, Ningxia, Hainan, Qinghai and Xizang were on the contrary. This paper suggests governments to enhance or ease to industrial VOCs reduction burden of each province in order to stimulate its economy or change its way of economy development.


Asunto(s)
Contaminantes Atmosféricos/análisis , Compuestos Orgánicos Volátiles/análisis , Contaminación del Aire/estadística & datos numéricos , China , Desarrollo Económico , Industrias
8.
Appl Environ Microbiol ; 81(14): 4626-33, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25934625

RESUMEN

Many reductive dehalogenases (RDases) have been identified in organohalide-respiring microorganisms, and yet their substrates, specific activities, and conditions for expression are not well understood. We tested whether RDase expression varied depending on the substrate-exposure history of reductive dechlorinating communities. For this purpose, we used the enrichment culture KB-1 maintained on trichloroethene (TCE), as well as subcultures maintained on the intermediates cis-dichloroethene (cDCE) and vinyl chloride (VC). KB-1 contains a TCE-to-cDCE dechlorinating Geobacter and several Dehalococcoides strains that together harbor many of the known chloroethene reductases. Expressed RDases were identified using blue native polyacrylamide gel electrophoresis, enzyme assays in gel slices, and peptide sequencing. As anticipated but never previously quantified, the RDase from Geobacter was only detected transiently at the beginning of TCE dechlorination. The Dehalococcoides RDase VcrA and smaller amounts of TceA were expressed in the parent KB-1 culture during complete dechlorination of TCE to ethene regardless of time point or amended substrate. The Dehalococcoides RDase BvcA was only detected in enrichments maintained on cDCE as growth substrates, in roughly equal abundance to VcrA. Only VcrA was detected in subcultures enriched on VC. Enzyme assays revealed that 1,1-DCE, a substrate not used for culture enrichment, afforded the highest specific activity. trans-DCE was substantially dechlorinated only by extracts from cDCE enrichments expressing BvcA. RDase gene distribution indicated enrichment of different strains of Dehalococcoides as a function of electron acceptor TCE, cDCE, or VC. Each chloroethene reductase has distinct substrate preferences leading to strain selection in mixed communities.


Asunto(s)
Proteínas Bacterianas/química , Chloroflexi/enzimología , Etilenos/metabolismo , Hidrolasas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Chloroflexi/química , Chloroflexi/genética , Etilenos/química , Halogenación , Hidrolasas/genética , Hidrolasas/metabolismo , Especificidad por Sustrato
9.
Am J Ind Med ; 58(1): 101-11, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25351791

RESUMEN

BACKGROUND: Healthcare workers have an elevated prevalence of asthma and related symptoms associated with the use of cleaning/disinfecting products. The objective of this study was to identify and characterize cleaning/disinfecting tasks and products used among hospital occupations. METHODS: Workers from 14 occupations at five hospitals were monitored for 216 shifts, and work tasks and products used were recorded at five-minute intervals. The major chemical constituents of each product were identified from safety data sheets. RESULTS: Cleaning and disinfecting tasks were performed with a high frequency at least once per shift in many occupations. Medical equipment preparers, housekeepers, floor strippers/waxers, and endoscopy technicians spent on average 108-177 min/shift performing cleaning/disinfecting tasks. Many occupations used products containing amines and quaternary ammonium compounds for >100 min/shift. CONCLUSIONS: This analysis demonstrates that many occupations besides housekeeping incur exposures to cleaning/disinfecting products, albeit for different durations and using products containing different chemicals.


Asunto(s)
Desinfección/estadística & datos numéricos , Personal de Salud/estadística & datos numéricos , Servicio de Limpieza en Hospital/estadística & datos numéricos , Exposición Profesional/estadística & datos numéricos , Control de Enfermedades Transmisibles/métodos , Detergentes/química , Detergentes/uso terapéutico , Desinfectantes/química , Desinfectantes/uso terapéutico , Desinfección/métodos , Personal de Salud/clasificación , Hospitales , Hospitales de Enseñanza , Humanos , Ficha de Datos de Seguridad de Materiales , New England , Exposición Profesional/análisis , Sudeste de Estados Unidos
10.
Zhonghua Nan Ke Xue ; 21(12): 1077-81, 2015 Dec.
Artículo en Zh | MEDLINE | ID: mdl-26817298

RESUMEN

OBJECTIVE: To investigate how network education can improve college students' knowledge on sexual and reproductive health in Ningbo city. METHODS: From December 2012 to June 2013, we conducted a questionnaire investigation among college students in Ningbo city about the effects of network education on their knowledge about sexual psychology, sexual physiology, sexual ethics, and reproductive health. RESULTS: A total of 7 362 college students accomplished the investigation, of whom 2 483 (42.1% males and 57.9% females) received network education, while the other 4 879 (24.1% males and 75.9% females) did not. Approximately 47.1% of the male and 28.0% of the female students acquired sexual and reproductive knowledge via network education. Reproductive health-related network education significantly enriched the students' knowledge about the reproductive system and sex, pubertal development, sexual physiology, conception and embryonic development, methods of contraception, sexual psychology, sexually transmitted diseases and their prevention, pregnancy care and eugenics, and environment- and occupation-related reproductive health (P < 0.01). It also remarkably improved their cognitive attitude towards reproductive health knowledge (P < 0.01). Those who received reproductive health-related network education showed a significantly higher rate of masturbation (P < 0.01) but markedly later time of the first masturbation (P < 0.01) than those who did not. CONCLUSION: Network education can enhance the effect of reproductive health education among college students and improve their sexual experience and health.


Asunto(s)
Educación en Salud , Conocimientos, Actitudes y Práctica en Salud , Salud Reproductiva , Conducta Sexual , Estudiantes , China , Anticoncepción , Femenino , Humanos , Masculino , Masturbación , Embarazo , Reproducción , Conducta Sexual/fisiología , Conducta Sexual/psicología , Enfermedades de Transmisión Sexual , Encuestas y Cuestionarios , Universidades
11.
Environ Sci Technol ; 48(9): 4844-51, 2014 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-24758692

RESUMEN

Chlorinated benzenes are ubiquitous organic contaminants found in groundwater and soils. Compound specific isotope analysis (CSIA) has been increasingly used to assess natural attenuation of chlorinated contaminants, in which anaerobic reductive dechlorination plays an essential role. In this work, carbon isotope fractionation of the three dichlorobenzene (DCB) isomers was investigated during anaerobic reductive dehalogenation in methanogenic laboratory microcosms. Large isotope fractionation of 1,3-DCB and 1,4-DCB was observed while only a small isotope effect occurred for 1,2-DCB. Bulk enrichment factors (εbulk) were determined from a Rayleigh model: -0.8 ± 0.1 ‰ for 1,2-DCB, -5.4 ± 0.4 ‰ for 1,3-DCB, and -6.3 ± 0.2 ‰ for 1,4-DCB. εbulk values were converted to apparent kinetic isotope effects for carbon (AKIE) in order to characterize the carbon isotope effect at the reactive positions for the DCB isomers. AKIE values are 1.005 ± 0.001, 1.034 ± 0.003, and 1.039 ± 0.001 for 1,2-DCB, 1,3-DCB, and 1,4-DCB, respectively. The large difference in AKIE values between 1,2-DCB and 1,3-DCB (or 1,4-DCB) suggests distinct reaction pathways may be involved for different DCB isomers during microbial reductive dechlorination by the methanogenic cultures.


Asunto(s)
Biodegradación Ambiental , Clorobencenos/metabolismo , Anaerobiosis , Isótopos de Carbono/química , Isótopos de Carbono/metabolismo , Fraccionamiento Químico , Clorobencenos/química , Isomerismo , Cinética
12.
Int Arch Occup Environ Health ; 87(4): 423-32, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23670403

RESUMEN

PURPOSE: Exacerbation is a critical event in asthma management. We investigated whether exacerbation of symptoms is associated with farming exposures among agricultural pesticide applicators with asthma. METHODS: Participants were pesticide applicators with active asthma (wheezing and breathing problems in past 12 months) who completed enrollment questionnaires for the Agricultural Health Study (AHS). Exacerbation of asthma was defined as having visited a hospital emergency room or doctor for an episode of wheezing or whistling in the past 12 months. Exposures of interest were using 36 specific pesticides in the past 12 months and conducting various agricultural activities. Adjusted odds ratios (ORs) were estimated by logistic regression while controlling for potential confounders. RESULTS: The 926 AHS adult pesticide applicators with active asthma included 202 (22%) with exacerbation. Inverse associations with exacerbation were observed for two herbicides [glyphosate, odds ratio (OR) = 0.5, 95% confidence interval (CI) 0.3, 0.8, and paraquat, OR = 0.3, 95% CI 0.1, 0.9] and several agricultural activities (repairing engines, grinding metal, driving diesel tractors, and performing veterinary procedures). Only asthma cases with allergies (i.e., doctor-diagnosed hay fever or eczema, 46%) had positive exacerbation-pesticide associations, with OR = 2.1 (95% CI 1.1, 4.1) for the herbicide pendimethalin and OR = 10.2 (95% CI 1.9, 55) for the insecticide aldicarb. CONCLUSIONS: The inverse associations with two pesticides and specific farm activities are consistent with the possibility that asthma cases prone to exacerbation may avoid exposures that trigger symptoms. Although limited by small sample size and a cross-sectional design, our study suggests that use of specific pesticides may contribute to exacerbation of asthma among individuals with allergies.


Asunto(s)
Enfermedades de los Trabajadores Agrícolas/etiología , Asma Ocupacional/etiología , Exposición Profesional/efectos adversos , Plaguicidas/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades de los Trabajadores Agrícolas/epidemiología , Asma Ocupacional/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Estados Unidos , Adulto Joven
13.
Chaos ; 24(3): 033113, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25273193

RESUMEN

Recently, the impacts of spatiotemporal heterogeneities of human activities on spreading dynamics have attracted extensive attention. In this paper, we intend to understand how the heterogeneous distribution of response times at the individual level influences information spreading. Based on the uncorrelated scale-free networks without degree-degree correlation, we study the susceptible-infected spreading dynamics with adjustable power-law response time distribution, and find that the stronger the heterogeneity of response times is, the faster the information spreading is in the early and middle stages. Following a given heterogeneity, the procedure of reducing the correlation between the response times and degrees of individuals can also accelerate the spreading dynamics in the early and middle stages. However, the dynamics in the late stage is slightly more complicated, and there is an optimal value of the full prevalence time (i.e., the time for full infection on a network) changing with the heterogeneity of response times and the response time-degree correlation, respectively. The optimal phenomena result from the efficient allocation of heterogeneous response times.

14.
Huan Jing Ke Xue ; 45(2): 909-919, 2024 Feb 08.
Artículo en Zh | MEDLINE | ID: mdl-38471929

RESUMEN

Based on the typical city survey data and statistics of Guangdong Province, a 2018-based 3 km×3 km gridded greenhouse gas emissions inventory was developed for Guangdong Province using the combination of top-down and bottom-up emission factor methods. The inventory covered the CO2, CH4, and N2O emissions from energy, industrial processes, agriculture, land use change and forest, waste management, and indirect sources. The results showed that estimates for CO2, CH4, and N2O in Guangdong Province for the year 2018 were 8.5×108, 1.9×106, and 1.1×105 t, respectively, and 8.5×108, 4.0×107, and 3.4×107 t by equivalent carbon dioxide, totaling 9.2×108 t. CO2 was the main greenhouse gas in Guangdong Province, accounting for 92.0% of the total emissions. Energy and indirect sources were the main emission sources, accounting for 77.9% and 7.6%, respectively, totaling 85.5%. Spatial distributions illustrated that most grids were greenhouse gas emissions, whereas some others were greenhouse gas sinks; the greenhouse gas emissions were distributed mainly in the Pearl River Delta region and had certain characteristics of distribution along the road network and channels. The greenhouse gas grids of high emission were mainly the locations of high energy-consuming enterprises such as large power plants, steel mills, and cement plants.

15.
Appl Environ Microbiol ; 79(3): 974-81, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23204411

RESUMEN

Dehalococcoides mccartyi strains are obligate organohalide-respiring bacteria harboring multiple distinct reductive dehalogenase (RDase) genes within their genomes. A major challenge is to identify substrates for the enzymes encoded by these RDase genes. We demonstrate an approach that involves blue native polyacrylamide gel electrophoresis (BN-PAGE) followed by enzyme activity assays with gel slices and subsequent identification of proteins in gel slices using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). RDase expression was investigated in cultures of Dehalococcoides mccartyi strain BAV1 and in the KB-1 consortium growing on chlorinated ethenes and 1,2-dichloroethane. In cultures of strain BAV1, BvcA was the only RDase detected, revealing that this enzyme catalyzes the dechlorination not only of vinyl chloride, but also of all dichloroethene isomers and 1,2-dichloroethane. In cultures of consortium KB-1, five distinct Dehalococcoides RDases and one Geobacter RDase were expressed under the conditions tested. Three of the five RDases included orthologs to the previously identified chlorinated ethene-dechlorinating enzymes VcrA, BvcA, and TceA. This study revealed substrate promiscuity for these three enzymes and provides a path forward to further explore the largely unknown RDase protein family.


Asunto(s)
Chloroflexi/enzimología , Halógenos/metabolismo , Hidrolasas/química , Hidrolasas/metabolismo , Electroforesis en Gel de Poliacrilamida Nativa , Chloroflexi/crecimiento & desarrollo , Chloroflexi/metabolismo , Cromatografía Liquida , Medios de Cultivo/química , ADN Bacteriano/química , ADN Bacteriano/genética , Hidrocarburos Clorados/metabolismo , Hidrolasas/aislamiento & purificación , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Especificidad por Sustrato , Espectrometría de Masas en Tándem
16.
Environ Sci Technol ; 47(5): 2378-85, 2013 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-23360185

RESUMEN

Chlorobenzene is a widespread groundwater contaminant found at many industrial sites. Reductive dechlorination of chlorobenzene requires input of electron donor and results in problematic accumulation of benzene, which is more toxic than chlorobenzene. We hypothesized that coupling a culture capable of reductive dechlorination of chlorobenzene to benzene with a second benzene-degrading methanogenic culture would completely detoxify chlorobenzene. To this end, active chlorobenzene-dechlorinating microcosms that were producing benzene were inoculated with a previously described enriched methanogenic benzene-degrading consortium. The combination resulted in the transformation of chlorobenzene via benzene to the nontoxic degradation products, CO2 and CH4. Sustainable degradation of chlorobenzene and benzene was observed in the microcosms and was further confirmed by shifts in the carbon isotopic ratios of chlorobenzene and benzene during degradation. Moreover, we could show that benzene derived electrons fueled chlorobenzene dechlorination removing the need to provide exogenous electron donor. The results have promising implications for sustainable bioremediation of sites contaminated with chlorinated benzenes and benzene.


Asunto(s)
Bacterias Anaerobias/metabolismo , Benceno/metabolismo , Dióxido de Carbono/química , Clorobencenos/metabolismo , Metano/química , Contaminantes Químicos del Agua/metabolismo , Anaerobiosis , Benceno/química , Biodegradación Ambiental , Clorobencenos/química , Electrones , Halogenación , Contaminantes Químicos del Agua/química
17.
Am J Ind Med ; 56(3): 300-7, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23109040

RESUMEN

BACKGROUND: We evaluated the effectiveness of workplace changes to prevent indium lung disease, using 2002-2010 surveillance data collected by an indium-tin oxide production facility. METHODS: We assessed pulmonary function using lower limits of normal. Blood indium concentration and personal air sampling data were used to estimate exposure. RESULTS: Abnormalities were uncommon at hire. After hire, prevalence of spirometric restriction was 31% (n = 14/45), about fourfold higher than expected. Excessive decline in FEV1 was elevated at 29% (n = 12/41). Half (n = 21/42) had blood indium ≥5 µg/l. More recent hires had fewer abnormalities. There was a suggestion that abnormalities were more common among workers with blood indium ≥5 µg/l, but otherwise an exposure-response relationship was not evident. Peak dust concentrations were obscured by time averaging. CONCLUSIONS: Evolving lung function abnormalities consistent with subclinical indium lung disease appeared common and merit systematic investigation. Traditional measures of exposure and response were not illustrative, suggesting fresh approaches will be needed. Workplace changes seemed to have had a positive though incomplete impact; novel preventive interventions are warranted.


Asunto(s)
Contaminantes Ocupacionales del Aire/efectos adversos , Indio/efectos adversos , Enfermedades Pulmonares Intersticiales/prevención & control , Enfermedades Profesionales/prevención & control , Exposición Profesional/prevención & control , Salud Laboral , Compuestos de Estaño/efectos adversos , Adulto , Contaminantes Ocupacionales del Aire/análisis , Contaminantes Ocupacionales del Aire/sangre , Biomarcadores/sangre , Volumen Espiratorio Forzado , Humanos , Indio/análisis , Indio/sangre , Modelos Logísticos , Enfermedades Pulmonares Intersticiales/sangre , Enfermedades Pulmonares Intersticiales/inducido químicamente , Enfermedades Pulmonares Intersticiales/diagnóstico , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Enfermedades Profesionales/inducido químicamente , Enfermedades Profesionales/diagnóstico , Exposición Profesional/efectos adversos , Exposición Profesional/análisis , Vigilancia de la Población , Evaluación de Programas y Proyectos de Salud , Espirometría , Factores de Tiempo
18.
Chaos ; 23(4): 043113, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24387552

RESUMEN

It has been found that noise plays a key role to improve signal transmission in a one-way chain of bistable systems [Zhang et al., Phys. Rev. E 58, 2952 (1998)]. We here show that the signal transmission can be sharply improved without the aid of noise, if the one-way chain with a single source node is changed with two source nodes becoming a Y-shaped one-way chain. We further reveal that the enhanced signal transmission in the Y-shaped one-way chain is regulated by coupling strength, and that it is robust to noise perturbation and input signal irregularity. We finally analyze the mechanism of the enhanced signal transmission by the Y-shaped structure.


Asunto(s)
Modelos Teóricos , Transducción de Señal , Relación Señal-Ruido , Procesos Estocásticos
19.
Sci Total Environ ; 904: 166416, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37659552

RESUMEN

China became the world leader in crude oil processing capacity in 2021. However, petroleum refining generates significant volatile organic compound (VOC) emissions, and the composite source profile, source-specific emission factors, and emission inventories of VOCs in the petroleum refining industry remain poorly understood. In this study, we focused on Guangdong, China's major province for crude oil processing, and systematically evaluated the historical emissions and reduction of VOCs in the petroleum refining industry from 2001 to 2020. We accomplished this by establishing local source-specific emission factors and composite source profiles. Finally, we quantitatively assessed the potential impact of these emissions on ozone and secondary organic aerosol formation. Our results revealed that VOC emissions from the petroleum refining industry in Guangdong followed an increasing-then-decreasing trend from 2001 to 2020, peaking at 37.3 Gg in 2016 and declining to 18.7 Gg in 2020. Storage tanks and wastewater collection and treatment remained the two largest sources, accounting for 41.9 %-53.4 % and 20.6 %-27.5 % of total emissions, respectively. Initially, Guangzhou and Maoming made the most significant contributions, with Huizhou becoming a notable contributor after 2008. Emission reduction efforts for VOCs in Guangdong's petroleum refining industry began showing results in 2017, with an average annual VOC emission reduction of 21.5 Gg from 2017 to 2020 compared to the unabated scenario. Storage tanks, wastewater collection and treatment, and loading operations were the primary sources of emission reduction, with significant contributions from Maoming, Huizhou, and Guangzhou. Alkanes made the largest contribution to VOC emissions, while alkenes/alkynes and aromatics comprised the most significant portions of ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAP). We also estimated VOC emissions and reduction from petroleum refining for China from 2001 to 2020, and measures such as "one enterprise, one policy" and deep control strategies could reduce emissions by at least 103.9 Gg.

20.
Sci Total Environ ; 866: 161295, 2023 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-36592911

RESUMEN

Printing industry is one of the most important sources of industrial volatile organic compound (VOC) emissions in China, and is thus a key industrial sector in terms of VOC control. However, process-based VOC emission and speciation from the printing industry have not been well identified, mainly owing to the poor emission factors (EFs) and diversity of source profiles. In this study, we systematically characterized process-based VOC emissions from the printing industry for the period of 2010-2019, through the establishment of improved emission factors and composite source profiles. VOC emissions from the printing industry were found to continuously increase from 2010 to 2018, reaching their maximum in 2018 at 939.8 Gg, but started to decrease afterwards. The substantial growth is driven by the large demand for ink and adhesive and the absence of effective control measures in the printing industry. The total VOC emissions and ozone formation potential (OFP) in China in 2019 were 916.1 Gg and 1834.5 Gg, respectively. Gravure printing and the compound process were the processes that contributed the most to both emissions and OFP. Rapidly developing provinces such as Guangdong, Jiangsu, and Zhejiang were the largest contributors to emissions. Oxygenated VOCs (OVOCs) accounted for most of the VOC emissions, followed by alkanes and aromatics, while aromatics were the dominant groups for total OFP, followed by alkenes/alkynes and OVOCs. Ethyl acetate, toluene, isopropanol, isopentane, and n-pentane were the top five VOC species in terms of emissions, while toluene, ethyl acetate, 1,3-butadiene, isopentane, and 1-butene were the top five species in terms of OFP. Scientific and precise control policy were proposed, involving four aspects: environmental access, emission standards, classification and management, and research on source substitution. We believe our study will provide an important reference for the systematic characterization and control policy of VOC emissions from other industries.

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