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1.
Noise exposure has been linked to several health outcomes including obesity. This cross-sectional study examined the association between occupational noise exposure and body mass index as a measure of general obesity in 913 textile workers (totally from nine factories) in Yazd city, Iran, from winter to summer of 2018. The sound pressure level (dBA) at each working station was measured by a calibrated sound level meter. The long-term noise exposure score of each worker (as dBA.year) was calculated by multiplying the working history in each unit to its corresponding noise level. Models were adjusted for personal, behavioral, environmental, and family history factors. In total, 81.05% (n?=?740) of the participants were exposed to noise levels higher than 85 dBA. The direct association was found for the fully adjusted model (β?=?0.002; 95% CI: 0.001: 0.004). For the model with past year noise exposure, a 10.6% increase in odds was observed for each 5 dBA increase in noise exposure (95% CI: 1.005: 1.216). We found a 0.1% increase in the odds of being overweight in mixed-gender analysis (95% CI: 1.001:1.002) for each 5 dBA.year in the fully adjusted model. Occupational noise exposure should be regarded as a risk factor for cardiometabolic outcomes in industrial workers. 相似文献
2.
The national Environmental Protection Agency is expected to issue its recommendations on noise legislation some time during the latter part of 1973. This agency will assume primary responsibility for enforcing noise limits on new products, such as vehicles, construction equipment, electrical equipment, etc. Primary responsibility for community noise control will remain with local governments. Local EPA’s, now involved in air and water pollution, will be given the additional responsibility to enforce anti-noise legislation.This legislation will cover noise emissions fromvehicles, industries, construction equipment, residential air conditioners, and power equipment, and the noises that pervade multifamily dwellings. Responsibility for controlling aircraft noise will be shared with the FAA. The noise ratings used in this legislation must be capable of easy measurement and yet correlate well with subjective response. For most noises the decibel level read on the A-scale of a sound level meter (dBA) is adequate. For aircraft noise a more complex rating scale must be used which includes consideration of the duration of the noise and the presence of a pure tone (engine whine). For still other noises (industries, construction) some consideration must be given to the total daily exposure time of the noise, along with its dBA rating. New community noise ordinances will draw on the research and experience associated with the present Chicago, III., ordinance. Some modifications of this ordinance are expected, however, to improve enforcement procedures and to lower vehicle noise levels, which are considered the worst of all the community noise pollutants. 相似文献
3.
Yanbu, on the Red Sea, is an affluent Saudi Arabian industrial city of modest size. Substantial effort has been spent to balance environmental quality, especially air pollution, and industrial development. We have analyzed six years of observations of criteria pollutants O 3, SO 2, particles (PM 2.5 and PM 10) and the known ozone precursors—volatile organic compounds (VOCs) and nitrogen oxides (NO x). The results suggest frequent VOC-limited conditions in which ozone concentrations increase with decreasing NO x and with increasing VOCs when NO x is plentiful. For the remaining circumstances ozone has a complex non-linear relationship with the VOCs. The interactions between these factors at Yanbu cause measurable impacts on air pollution including the weekend effect in which ozone concentrations stay the same or even increase despite significantly lower emissions of the precursors on the weekends. Air pollution was lower during the Eids (al-Fitr and al-Adha), Ramadan and the Hajj periods. During Ramadan, there were substantial night time emissions as the cycle everyday living is almost reversed between night and day. The exceedances of air pollution standards were evaluated using criteria from the U.S. Environmental Protection Agency (EPA), World Health Organization (WHO), the Saudi Presidency of Meteorology and Environment (PME) and the Royal Commission Environmental Regulations (RCER). The latter are stricter standards set just for Yanbu and Jubail. For the fine particles (PM 2.5), an analysis of the winds showed a major impact from desert dust. This effect had to be taken into account but still left many occasions when standards were exceeded. Fewer exceedances were found for SO 2, and fewer still for ozone. The paper presents a comprehensive view of air quality at this isolated desert urban environment. Implications: Frequent VOC-limited conditions are found at Yanbu in Saudi Arabia that increase ozone pollution if NOx is are reduced. In this desert environment, increased nightlife produces the highest levels of VOCs and NOx at night rather than the day. The effects increase during Ramadan. Fine particles peak twice a day—the morning peak is caused by traffic and increases with decreasing wind, potentially representing health concerns, but the larger afternoon peak is caused by the wind, and it increases with increasing wind speeds. These features suggest that exposure to pollutants must be redefined for such an environment. 相似文献
4.
ABSTRACT Equations derived previously for critical downwind distance x , wind speed u , and plume rise z , the values that produce maximum ground-level concentrations (MGLC) Xc under downwash conditions, have been solved. Tables of %c, xc, uc, and z c, and graphs of the relationships among uc and zc for a range of stack heights hs, and building heights hb, are presented. Results for two types of sources— a turbine and a reciprocating engine—are discussed. Some comparisons are made to the U.S. Environmental Protection Agency's (EPA) SCREEN3 model. 相似文献
5.
介绍了中小型工业窑炉生产过程中排放NOx的现状,并针对NOx的治理问题,从工程应用角度,简述了湿法和干法净化NOx的原理和化学反应过程。讨论了NOx排放特性和NOx废气中NO2/NOx比例的问题。提出了影响NOx治理的主要因素,包括吸收剂、吸附剂、催化剂和设备的部分应用参数,并结合工程实例指出工程需要注意的问题。介绍了多项采用湿法和干法净化NOx的工程应用项目,丰富了中小工业窑炉NOx废气的治理的实践经验,为中小工业窑炉排放NOx治理奠定了基础。 相似文献
6.
The body of information presented in this paper is directed to those individuals concerned with the location of highways relative to either existing or planned residential communities. The paper treats in depth the expected attenuation of automobile and particularly diesel tractor-trailer generated hoise by the interposition of extensive and dense planting of trees and shrubs between the highway and the community. The results of research, by the author and others cited in the paper, gives clear indication that a belt of dense man-made growth of tall trees and underbrush can give as much as 5 to 8 dB truck/car noise reduction per 100 ft of planting depth. Natural growth of deep forests were measured to give from 3 to 5 dB attenuation per 100 ft of planting depth. Planting depth of at least 100 ft is required to give reliable results, with tree heights of 40-50 ft desirable and densities of 50-70 ft visibility needed for good effect. The paper provides considerable experimental verification by an analysis of the current literature. The types of noise sources in cars and trucks are briefly treated as are community reactions to noise from such sources. The dBA is used as the accepted measure for characterizing truck and automobile noise. Both spherical and cylindrical radiation of sound are discussed for low density and high density traffic, respectively. The paper concludes with an example of attenuation of a typical truck noise by spherical and cylindrical radiation for low- and high-density traffic and a 200-ft deep planting of dense, mature forest. It is concluded that a mature belt of either coniferous or deciduous forest with underbrush can produce barely acceptable noise levels in the community which is separated by such a noise barrier from a heavily traveled highway. 相似文献
7.
The Interstate Air Pollution Study of the St. Louis-East St. Louis Metropolitan Area, conducted in 1963–1964, provided data for this report of air pollutant emissions related to three land-use categories: (1) residential, (2) institutional and commercial, and (3) industrial. A fourth land-use category, transportation and open space, is included in some calculations. The sources of pollutants considered are: (1) power generation, both electric utilities and industrial, (2) fuels used for space heating, (3) solid waste disposal, and (4) industrial processes. The pollutant emissions considered are particulates and sulfur oxides. Cumulative frequency distributions given are based on acres of land use and corresponding emissions per unit area. These frequency distributions—actual emission conditions that can be related to known air quality levels—provide a basis for performance standards and a guide for planners and others in future city developments, not only in St. Louis but in other similar cities as well. A suggested method for determining a different type performance zoning standard is presented. This standard is based on average conditions and thus would supplement, not replace, standards based on maximum allowable emissions. Calculations for such standards relating to St. Louis are presented. 相似文献
8.
The Environmental Protection Agency is responsible for establishing, reviewing, and revising standards of performance for new stationary sources of air pollution. Since this federal program was authorized in 1970, standards of performance (commonly referred to as new source performance standards or NSPS) have been developed for 34 categories of stationary sources. These regulations have focused primarily on large new sources of particulate matter, NO x , and SO 2 emissions. Recently, work has begun on NSPS for a number of source categories that emit volatile organic compounds. Environmental professionals in these industries and in many regulatory agencies have little direct experience with the NSPS program and are unaware of the detailed engineering, cost, and economic information available with each proposed rulemaking. This article, therefore, reviews the purposes, procedures, and benefits of the NSPS program. A summary of the NSPS that have been promulgated through February 1983 are presented in tabular form. 相似文献
9.
Map Ta Phut industrial area (MA) is the largest industrial complex in Thailand. There has been concern about many air pollutants over this area. Air quality management for the area is known to be difficult, due to lack of understanding of how emissions from different sources or sectors (e.g., industrial, power plant, transportation, and residential) contribute to air quality degradation in the area. In this study, a dispersion study of NO 2 and SO 2 was conducted using the AERMOD model. The area-specific emission inventories of NO x and SO 2 were prepared, including both stack and nonstack sources, and divided into 11 emission groups. Annual simulations were performed for the year 2006. Modeled concentrations were evaluated with observations. Underestimation of both pollutants was found, and stack emission estimates were scaled to improve the modeled results before quantifying relative roles of individual emission groups to ambient concentration over four selected impacted areas (two are residential and the others are highly industrialized). Two concentration measures (i.e., annual average area-wide concentration or AC, and area-wide robust highest concentration or AR) were used to aggregately represent mean and high-end concentrations for each individual area, respectively. For AC-NO 2, on-road mobile emissions were found to be the largest contributor in the two residential areas (36–38% of total AC-NO 2), while petrochemical-industry emissions play the most important role in the two industrialized areas (34–51%). For AR-NO 2, biomass burning has the most influence in all impacted areas (>90%) except for one residential area where on-road mobile is the largest (75%). For AC-SO 2, the petrochemical industry contributes most in all impacted areas (38–56%). For AR-SO 2, the results vary. Since the petrochemical industry was often identified as the major contributor despite not being the largest emitter, air quality workers should pay special attention to this emission group when managing air quality for the MA. Implications: Effective air quality management in Map Ta Phut Industrial Area, Thailand requires better understanding of how emissions from various sources contribute to the degradation of ambient air quality. Based on the dispersion study here, petrochemical industry was generally identified as the major contributor to ambient NO 2 and SO 2. By accounting for all stack and non-stack sources, on-road mobile emissions were found to be important in some particular areas. 相似文献
10.
In a field study of 302 residences, the indoor air contaminant concentrations associated with the use of unvented kerosene space heaters and gas cooking stoves were measured. For each residence, 2-week average NO 2 levels were recorded outdoors and in three rooms using diffusion-type passive monitors. Data were obtained on NO 2 sources, the level of use of these sources and on building characteristics from an initial questionnaire, a bi-weekly telephone interview, daily diaries and from assessors' records. The methodology employed in the field study is evaluated in terms of a multivariate model which predicts variations in NO 2 levels in the residences as a function of the existence and reported use of sources. The source use parameters were found to explain over 60 % of the variation in residential indoor NO 2 levels. The levels of specification needed for other independent variables (infiltration, removal rates, etc.) and the source use terms in the predictive model are presented and discussed. 相似文献
11.
A highly resolved temporal and spatial Pearl River Delta (PRD) regional emission inventory for the year 2006 was developed with the use of best available domestic emission factors and activity data. The inventory covers major emission sources in the region and a bottom–up approach was adopted to compile the inventory for those sources where possible. The results show that the estimates for SO 2, NO x, CO, PM 10, PM 2.5 and VOC emissions in the PRD region for the year 2006 are 711.4 kt, 891.9 kt, 3840.6 kt, 418.4 kt, 204.6 kt, and 1180.1 kt, respectively. About 91.4% of SO 2 emissions were from power plant and industrial sources, and 87.2% of NO x emissions were from power plant and mobile sources. The industrial, mobile and power plant sources are major contributors to PM 10 and PM 2.5 emissions, accounting for 97.7% of the total PM 10 and 97.2% of PM 2.5 emissions, respectively. Mobile, biogenic and VOC product-related sources are responsible for 90.5% of the total VOC emissions. The emissions are spatially allocated onto grid cells with a resolution of 3 km × 3 km, showing that anthropogenic air pollutant emissions are mainly distributed over PRD central-southern city cluster areas. The preliminary temporal profiles were established for the power plant, industrial and on-road mobile sources. There is relatively low uncertainty in SO 2 emission estimates with a range of −16% to +21% from power plant sources, medium to high uncertainty for the NO x emissions, and high uncertainties in the VOC, PM 2.5, PM 10 and CO emissions. 相似文献
12.
In this study, air pollutants, including ozone (O 3), nitrogen oxides (NO x = NO + NO 2), carbon monoxides (CO), sulfur dioxide (SO 2), and volatile organic compounds (VOCs) measured in the Yangtze River Delta (YRD) region during several air flights between September/30 and October/11 are analyzed. This measurement provides horizontal and vertical distributions of air pollutants in the YRD region. The analysis of the result shows that the measured O 3 concentrations range from 20 to 60 ppbv. These values are generally below the US national standard (84 ppbv), suggesting that at the present, the O 3 pollutions are modest in this region. The NO x concentrations have strong spatial and temporal variations, ranging from 3 to 40 ppbv. The SO 2 concentrations also have large spatial and temporal variations, ranging from 1 to 35 ppbv. The high concentrations of CO are measured with small variations, ranging from 3 to 7 ppmv. The concentrations of VOCs are relatively low, with the total VOC concentrations of less than 6 ppbv. The relative small VOC concentrations and the relative large NO x concentrations suggest that the O 3 chemical formation is under a strong VOC-limited regime in the YRD region. The measured O 3 and NO x concentrations are strongly anti-correlated, indicating that enhancement in NO x concentrations leads to decrease in O 3 concentrations. Moreover, the O 3 concentrations are more sensitive to NO x concentrations in the rural region than in the city region. The ratios of Δ[O 3]/Δ[NO x] are ?2.3 and ?0.25 in the rural and in the city region, respectively. In addition, the measured NO x and SO 2 concentrations are strongly correlated, highlighting that the NO x and SO 2 are probably originated from same emission sources. Because SO 2 emissions are significantly originated from coal burnings, the strong correlation between SO 2 and NO x concentrations suggests that the NO x emission sources are mostly from coal burned sources. As a result, the future automobile increases could lead to rapid enhancements in O 3 concentrations in the YRD region. 相似文献
13.
ABSTRACT In August 1995, measurements of CO, NO x, speciated nonmethane hydrocarbons (NMHC), and CO 2 were made in Vancouver's Cassiar Connector, a 730-m-long level-grade highway traffic tunnel. Two characteristics of the Vancouver setting are the presence of many propane vehicles and a mandatory inspection and maintenance (I/M) program. Although the driving conditions and vehicle fleets are otherwise outwardly similar to those of recent Tuscarora-tunnel studies, CO/NO ratios at the Cassiar Connector are significantly lower than those measured at Tuscarora. The Cassiar measurements are consistent with the MOBILE5A mobile emissions model predictions. The Canadian version of MOBILE5A—known as MOBILE5C—gives nearly identical results, indicating that differences in Canadian and U.S. emission standards cannot explain differences between Cassiar and U.S. tunnels. Considering the modeling results as well as measured ethene/acetylene ratios indicative of noncatalyst vehicles, it appears that vehicle deterioration remains the major issue in in-use vehicle emissions—even in Vancouver, where there is a mandatory loaded-mode I/M program. 相似文献
14.
The effects of two alternative sources of animal fat-derived biodiesel feedstock on CO 2, CO, NO x tailpipe emissions as well as fuel consumption were investigated. Biodiesel blends were produced from chicken and swine fat waste (FW-1) or floating fat (FW-2) collected from slaughterhouse wastewater treatment processes. Tests were conducted in an unmodified stationary diesel engine operating under idling conditions in attempt to simulate slow traffic in urban areas. Significant reductions in CO (up to 47% for B100; FW-2) and NO x (up to 20% for B5; FW-2 or B100; FW-1) were attained when using biodiesel fuels at the expense of 5% increase in fuel consumption. Principal component analysis (PCA) was performed to elucidate possible associations among gas (CO 2, CO, and NO x) emissions, cetane number and iodine index with different sources of feedstock typically employed in the biodiesel industry. NO x, cetane number and iodine index were inversely proportional to CO 2 and biodiesel concentration. High NO x emissions were reported from high iodine index biodiesel derived especially from forestry, fishery and some agriculture feedstocks, while the biodiesel derived from animal sources consistently presented lower iodine index mitigating NO x emissions. The obtained results point out the applicability of biodiesel fuels derived from fat-rich residues originated from animal production on mitigation of greenhouse gas emissions. The information may encourage practitioners from biodiesel industry whilst contributing towards development of sustainable animal production. Implications: Emissions from motor vehicles can contribute considerably to the levels of greenhouse gases in the atmosphere. The use of biodiesel to replace or augment diesel can not only decrease our dependency on fossil fuels but also help decrease air pollution. Thus, different sources of feedstocks are constantly being explored for affordable biodiesel production. However, the amount of carbon monoxide (CO), carbon dioxide (CO2), and/or nitrogen oxide (NOx) emissions can vary largely depending on type of feedstock used to produce biodiesel. In this work, the authors demonstrated animal fat feasibility in replacing petrodiesel with less impact regarding greenhouse gas emissions than other sources. 相似文献
15.
This paper presents the temporal variation in surface-level ozone (O 3) measured at Gummidipoondi near Chennai, Tamilnadu. The site chosen for the present study has high potential for ozone generation sources, such as vehicular traffic and industrial activities. The site is also located near a hazardous waste management facility. The key sources of nitrogen oxides (NO x), which are considered to be an important precursor of O 3, include hazardous waste incineration, trucks bringing the hazardous wastes, and vehicles plying on the nearby National Highway 16 (NH 16). The measurements clearly showed diurnal variation, with maximum values observed during the noon hours and minimum values observed when solar radiation was less. The data showed a marked seasonal variation in O 3, with the highest hourly average O 3 concentration (497.2 µg/m 3) in the summer season. Consequently, in order to identify the long-range transport sources adding to the increased O 3 levels, backward trajectories were computed using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. It was found that the polluted air mass originated from the Southeast Asian region and the Indo-Gangetic Plain. The polluted air mass, which advected large amounts of carbon monoxide (CO) plumes, was analyzed using the Measurement of Pollution in the Troposphere (MOPITT) retrievals. The correlations of O 3 with temperature ( r = 0.746; P < 0.01) and solar radiation ( r = 0.751; P < 0.01) were strongly positive, and that with NO x was found to be negative. Stronger correlation of O 3 with NO x was observed during pre-monsoon months ( r = 0.627; P < 0.01) and following hours of photochemical reactions. There were substantial differences in concentrations between weekdays and weekends, with higher nitric oxide (NO) and nitrogen dioxide (NO 2), but lower O 3, concentrations on weekdays. A substantial weekday-weekend difference in O 3, which was higher on weekends, appears to be attributable to lower daytime traffic activity and hence reduced emissions of NO x to a “NO x-saturated” atmosphere. Implications: The assessment of ground-level ozone in an industrial area with hazardous waste management facility is very important, as there is high possibility for more generation of tropospheric ozone. Since the location of the study area is coastal, wind plays a major role in O 3 transportation; hence, the effects of wind speed and wind direction have been studied in different seasons. When compared with the other studies carried out in different places across India, the present study area has recorded much greater O 3 mixing ratio. This study can be useful for setting up control strategies in such industrial areas. 相似文献
16.
Abstract A remote sensing device was used to obtain on-road and in-use gaseous emission measurements from three fleets of schools buses at two locations in Washington State. This paper reports each fleet’s carbon monoxide (CO), hydrocarbon (HC), nitric oxide (NO), and nitrogen dioxide (NO 2) mean data. The fleets represent current emission retrofit technologies, such as diesel particulate filters and diesel oxidation catalysts, and a control fleet. This study shows that CO and HC emissions decrease with the use of either retrofit technology when compared with control buses of the same initial emission standards. The CO and HC emission reductions are consistent with published U.S. Environmental Protection Agency verified values. The total oxides of nitrogen (NO x), NO, and the NO 2/NO x ratio all increase with each retrofit technology when compared with control buses. As was expected, the diesel particulate filters emitted significantly higher levels of NO 2 than the control fleet because of the intentional conversion of NO to NO 2 by these systems. Most prior research suggests that NO x emissions are unaffected by the retrofits; however, these previous studies have not included measurements from retrofit devices on-road and after nearly 5 yr of use. Two 2006 model-year buses were also measured. These vehicles did not have retrofit devices but were built to more stringent new engine standards. Reductions in HCs and NO x were observed for these 2006 vehicles in comparison to other non-retrofit earlier model-year vehicles. 相似文献
17.
This paper evaluates the relative impact on air quality of harbour emissions, with respect to other emission sources located in the same area. The impact assessment study was conducted in the city of Taranto, Italy. This area was considered as representative of a typical Mediterranean harbour region, where shipping, industries and urban activities co-exist at a short distance, producing an ideal case to study the interaction among these different sources. Chemical and meteorological field campaigns were carried out to provide data to this study. An emission inventory has been developed taking into account industrial sources, traffic, domestic heating, fugitive and harbour emissions. A 3D Lagrangian particle dispersion model (SPRAY) has then been applied to the study area using reconstructed meteorological fields calculated by the diagnostic meteorological model MINERVE. 3D short term hourly concentrations have been computed for both all and specific sources. Industrial activities are found to be the main contributor to SO 2. Industry and traffic emissions are mainly responsible for NO x simulated concentrations. CO concentrations are found to be mainly related to traffic emissions, while primary PM 10 simulated concentrations tend to be linked to industrial and fugitive emissions. Contributions of harbour activities to the seasonal average concentrations of SO 2 and NO x are predicted to be up to 5 and 30 μg m −3, respectively to be compared to a overall peak values of 60 μg m −3 for SO 2 and 70 μg m −3 for NO x. At selected urban monitoring stations, SO 2 and NO x average source contributions are predicted to be both of about 9% from harbour activities, while 87% and 41% respectively of total concentrations are predicted to be of industrial origin. 相似文献
18.
Bursa is one of the largest cities of Turkey and it hosts 17 organized industrial zones. Parallel to the increase in population, rapidly growing energy consumption, and increased numbers of transport vehicles have impacts on the air quality of the city. In this study, regularly calibrated automatic samplers were employed to get the levels of air pollution in Bursa. The concentrations of CH 4 and N-CH 4 as well as the major air pollutants including PM 10, PM 2.5, NO, NO 2, NO x, SO 2, CO, and O 3, were determined for 2016 and 2017 calendar years. Their levels were 1641.62?±?718.25, 33.11?±?5.45, 42.10?±?10.09, 26.41?±?9.01, 19.47?±?16.51, 46.73?±?16.56, 66.23?±?32.265, 7.60?±?3.43, 659.397?±?192.73, and 51.92?±?25.63 µg/m 3 for 2016, respectively. Except for O 3, seasonal concentrations were higher in winter and autumn for both years. O 3, CO, and SO 2 had never exceeded the limit values specified in the regulations yet PM 10, PM 2.5, and NO 2 had violated the limits in some days. The ratios of CO/NO x, SO 2/NO x, and PM 2.5/PM 10 were examined to characterize the emission sources. Generally, domestic and industrial emissions were dominated in the fall and winter seasons, yet traffic emissions were effective in spring and summer seasons. As a result of the correlation process between O x and NO x, it was concluded that the most important source of O x concentrations in winter was NO x and O 3 was in summer. 相似文献
19.
A number of selected industrial processes considered as potential sources of benzo{a)- pyrene and other polynuclear hydrocarbons were surveyed. Polynuclear hydrocarbon emission levels were measured directly for asphalt hot road mix preparation and asphalt airblowing. Emissions of other pollutants, including particulate matter, carbon monoxide, and total gaseous hydrocarbons were also measured, and are reported together with pertinent data on process design and operation. Results are discussed with reference to the type of process; the type of equipment used, including control devices; and other factors. The significance of some additional processes as contributors of polynuclear hydrocarbons was examined indirectly by collecting atmospheric samples of polynuclear hydrocarbons in residential areas in the vicinity of (1) a carbon black manufacturing area, (2) a steel and coke manufacturing area, (3) an organic chemical industry complex, and (4) a residential and small-industry coal burning area. 相似文献
20.
Estimates of dermal permeability ( Kp), obtained by fitting an updated human PBPK model for malathion to previously reported data on excreted urinary metabolites after 29 volunteers were dermally exposed to measured values of [ 14C]malathion dermal load ( L), were used to examine the empirical relationship between Kp and L. The PBPK model was adapted from previously reported human biokinetic and PBPK models for malathion, fit to previously reported urinary excretion data after oral [ 14C]malathion intake by volunteers, and then augmented to incorporate a standard Kp approach to modeling dermal-uptake kinetics. Good to excellent PBPK-model fits were obtained to all of 29 sets of cumulative urinary metabolite-excretion data (ave. [±1 SD] R2 = 0.953 [±0.064]). Contrary to the assumption that Kp and L are independent typically applied for dermally administered liquids or solutions, the 29 PBPK-based estimates of Kp obtained for malathion exhibit a strong positive association with the 2/3rds power of L (log-log Pearson correlation = 0.925, p = ~0). Possible explanations of this observation involving physico-chemical characteristics and/or in vivo cutaneous effects of malathion are discussed. The PBPK model presented, and our observation that Kp estimates obtained by fitting this model to human experimental urinary-excretion data correlate well with L2/3, allow more realistic assessments of absorbed and metabolized dose during or after a variety of scenarios involving actual or potential dermal or multi-route malathion exposures, including for pesticide workers or farmers who apply malathion to crops. 相似文献
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