A comparison of household lead exposure assessment methods in an old,urban community

The accurate assessment of lead hazards within the household is critical to the prevention of lead exposure to children living in urban communities. Although dust wipes are currently accepted as the best method of assessing lead hazards, questionnaires and visual inspections are also used. This study evaluates the level of agreement among these three methods of assessment using a sample of 126 women living in old, urban houses. The level of agreement was assessed using the kappa statistic, which adjusts for chance agreement. Overall, the kappa results for both the participant's assessment (questionnaire) and the visual inspector's assessment were low, indicating only slight to moderate agreement with the dust lead wipe levels. Kappas were higher and more consistent for the visual inspector's assessment than for the participant's assessment. These results indicate that visual inspections and participant questionnaires may provide less accurate information regarding lead hazards within the household than dust wipes. Because lead hazard recognition is important in the prevention of lead exposure in children, our data suggest that emphasis should be placed on the measurement of dust lead levels directly in assessing household lead hazards, possibly by teaching women in high-risk neighborhoods to take dust samples themselves.     

Kriged and modeled ambient air levels of benzene in an urban environment: an exposure assessment study

Background  

There is increasing concern regarding the potential adverse health effects of air pollution, particularly hazardous air pollutants (HAPs). However, quantifying exposure to these pollutants is problematic.     

Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures

INTRODUCTION: A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of S?o Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant. OBJECTIVES: To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures. METHODS: Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure. RESULTS: Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL. CONCLUSIONS: This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.     

典型人群多环芳烃个体暴露特征和风险评估

目的考察典型人群多环芳烃(PAHs)多途径个体暴露特征与风险。方法采集研究对象工作环境24 h的颗粒物和三餐样本,收集个人活动日志以此来统计时间-活动模式,用GC-MS分析PAHs,以毒性等效剂量估算呼吸途径暴露PAHs的患癌风险。结果 5组研究对象呼吸途径PAHs的暴露量分别为:吸烟组0.04 mg/d,厨师组0.03mg/d,交通协管员组0.05 mg/d,上煤工组0.01 mg/d,对照组0.01 mg/d。饮食途径PAHs的暴露量分别为:吸烟组0.11 mg/d,厨师组0.09 mg/d,交通协管员组0.09 mg/d,上煤工组0.12 mg/d,对照组0.10 mg/d。5组研究对象呼吸途径暴露PAHs的患癌风险依次为:厨师(2.86×10-2)>交通协管员(2.18×10-2)>吸烟组(1.72×10-2)>上煤工组(1.14×10-2)>对照组(0.91×10-2)。结论食物是PAHs摄入的主要途径,4类典型人群由于PAHs暴露导致的患癌风险均很高(1×10-2～2×10-2),且吸烟与职业途径的PAHs暴露占呼吸途径暴露的主要部分,对于吸烟与职业环境的控制将有助于降低人群PAHs暴露水平。     

Accidental bromine exposure in an urban population: an acute epidemiological assessment

In November 1984, because of an accident at a chemical plant, the population of a large area in the town of Geneva, Switzerland, was exposed to toxic bromine gas during several hours at concentrations above the short-term exposure limit. We describe the development of the disaster, the reactions of the fire brigade, the police and the first aid services as well as the breakdown of communications that occurred. On-the-spot epidemiological assessment of the exposed area and of the characteristics of the exposure syndrome was combined with the emergency care of 91 self-referred patients that were seen at the University Hospital. Follow-up was obtained one month later. The clinical course was moderate (eyes and upper airways irritation) and self-limiting in all cases. Immediate definition of the exposed population permitted effective follow-up. Such early evaluation could prove to be of crucial importance for managing more serious accidents of a similar nature.     

Probabilistic risk assessment of cotton pyrethroids: V. Combining landscape-level exposures and ecotoxicological effects data to characterize risks

Since their introduction, synthetic pyrethroid insecticides have generated regulatory concerns regarding their toxicity to fish and aquatic invertebrates. In this paper we assess the potential for risks to aquatic ecosystems in cotton-growing areas, focusing on cypermethrin as a suitable representative of the pyrethroid class and static water bodies (ponds and lakes) as worst-case water bodies because of low levels of dilution. Reviews of cypermethrin effects under laboratory and field conditions have characterized the potential aquatic effects of the chemical. Also, a landscape-level exposure characterization has been conducted in a worst-case cotton-growing county, Yazoo County, Mississippi, USA, to provide a more realistic exposure characterization than is possible using standard model scenarios. Risks were characterized using the standard tier I and II approaches of the U.S. Environmental Protection Agency. In addition, a probabilistic risk assessment was conducted by comparing landscape-level exposure calculations for ponds and lakes in Yazoo County (modified tier II analysis) with distributions of laboratory effect concentrations and with data from field studies. Risk characterization using tier I and tier II models demonstrated a level of concern for certain aquatic organisms. However, modified tier II analysis showed that exposure concentrations are unlikely to exceed concentrations that might cause ecologically significant effects. Indeed, in the vast majority of cases, concentrations in the modified tier II analysis were several orders of magnitude lower than those at which effects would be predicted on the basis of laboratory and field data. The conclusion of minimal potential for adverse ecological effects was also supported by field studies, which showed that impacts on aquatic systems were negligible, even at concentrations many times higher than the modified tier II exposure concentrations.     

Personal exposure monitoring wearing protocol compliance: an initial assessment of quantitative measurement

Personal exposure sampling provides the most accurate and representative assessment of exposure to a pollutant, but only if measures are implemented to minimize exposure misclassification and reduce confounders that may cause misinterpretation of the collected data. Poor compliance with personal sampler wearing protocols can create positive or negative biases in the reported exposure concentrations, depending on proximity of the participant or the personal sampler to the pollutant source when the monitor was not worn as instructed. This paper presents an initial quantitative examination of personal exposure monitor wearing protocol compliance during a longitudinal particulate matter personal exposure monitoring study of senior citizens of compromise health in North Carolina. Wearing compliance varied between participants because of gender or employment status, but not longitudinally or between cohorts. A minimum waking wearing compliance threshold, 0.4 for this study of senior citizens, is suggested to define when personal exposure measurements are representative of a participant's exposure. The ability to define a minimum threshold indicates data weighting techniques may be used to estimate a participant's exposure assuming perfect protocol compliance.     

Personal exposure to atmospheric polycyclic aromatic hydrocarbons in a general adult population and lung cancer risk assessment

Personal exposure to nine particulate-phase atmospheric polycyclic aromatic hydrocarbons (PAHs) was assessed among adult non-smoking volunteers in the Grenoble, France, metropolitan area. Using Toxic Equivalency Factors, the associated total atmospheric PAHs lifelong cancer risk was estimated. For 48 hours continuously, 38 subjects without specific occupational exposure to combustion sources carried a PM2.5 particles personal exposure monitor while at home, at work, commuting, or involved in other activities. One phase of the study took place in summer; a second in winter. The monitor set was composed of a pump with an airflow of 4 L.mn-1, a 2.5-micron cyclone, and Teflon filters. The PAH concentrations were determined on seven PM2.5 filters by using high performance liquid chromatography with fluorimetric detection. The predominant PAHs are fluoranthene and indeno pyrene. According to the compound, the personal exposure estimates ranged from 0.13 to 1.67 ng/m3 (yearly means). The average benzo(a) pyrene value is 0.67 ng/m3 (95% confidence interval = 0 to 2.1 ng/m3). Winter exposures were 3 to 25 times greater than summer exposures. The total PAHs lung cancer lifelong risk is 7.8 10(-5) and is driven by exposure to benzo(a) pyrene. Although these risk estimates are 2 to 3 orders of magnitude lower than those associated with specific occupational exposures in the coal or smelter industries, they are of public health concern because they are spread over large urban populations. Further personal exposure studies in adult or children populations are needed.     

Cumulative organophosphate pesticide exposure and risk assessment among pregnant women living in an agricultural community: a case study from the CHAMACOS cohort

Approximately 230,000 kg of organophosphate (OP) pesticides are applied annually in California's Salinas Valley. These activities have raised concerns about exposures to area residents. We collected three spot urine samples from pregnant women (between 1999 and 2001) enrolled in CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas), a longitudinal birth cohort study, and analyzed them for six dialkyl phosphate metabolites. We used urine from 446 pregnant women to estimate OP pesticide doses with two deterministic steady-state modeling methods: method 1, which assumed the metabolites were attributable entirely to a single diethyl or dimethyl OP pesticide; and method 2, which adapted U.S. Environmental Protection Agency (U.S. EPA) draft guidelines for cumulative risk assessment to estimate dose from a mixture of OP pesticides that share a common mechanism of toxicity. We used pesticide use reporting data for the Salinas Valley to approximate the mixture to which the women were exposed. Based on average OP pesticide dose estimates that assumed exposure to a single OP pesticide (method 1), between 0% and 36.1% of study participants' doses failed to attain a margin of exposure (MOE) of 100 relative to the U.S. EPA oral benchmark dose(10) (BMD(10)), depending on the assumption made about the parent compound. These BMD(10) values are doses expected to produce a 10% reduction in brain cholinesterase activity compared with background response in rats. Given the participants' average cumulative OP pesticide dose estimates (method 2) and regardless of the index chemical selected, we found that 14.8% of the doses failed to attain an MOE of 100 relative to the BMD(10) of the selected index. An uncertainty analysis of the pesticide mixture parameter, which is extrapolated from pesticide application data for the study area and not directly quantified for each individual, suggests that this point estimate could range from 1 to 34%. In future analyses, we will use pesticide-specific urinary metabolites, when available, to evaluate cumulative OP pesticide exposures.     

两种风险评估方法在粉尘职业健康风险评估中的应用比较

  目的  比较两种风险评估方法对粉尘工作岗位职业健康风险评估的结果,探讨其适用性。
  方法  分别选取广州市某汽车制造企业、某家具制造企业和某煤码头生产过程中产生粉尘的典型岗位为研究对象,开展现场职业卫生调查、工作场所典型岗位粉尘浓度检测,应用国内《工作场所化学有害因素职业健康风险评估技术导则》（GBZ/T 298—2017）中推荐的半定量综合指数法和国际采矿与金属委员会定量职业健康风险评估法（ICMM定量法）分别对各企业粉尘岗位进行职业健康风险评估,并对两种方法的评估结果进行比较。
  结果  半定量综合指数法评估汽车制造企业二氧化碳焊岗位电焊烟尘、煤码头卸船、输送带巡检、堆料、清扫、装船岗位煤尘为低风险,汽车制造企业电阻焊岗位为中等风险,家具制造企业开料、铣边、开孔、水磨、加工岗位矽尘为高风险;ICMM定量法评估汽车制造企业焊接岗位电焊烟尘为潜在风险,煤码头卸船、输送带巡检、堆料、装船岗位煤尘为非常高风险,家具制造企业5个岗位及煤码头清扫岗位为不可容忍风险;ICMM定量法所得评估结果大部分高于半定量综合指数法。
  结论  两种评估方法均能在一定程度上评估和预测粉尘的职业健康风险。ICMM定量法评估结果更为严格;半定量综合指数法综合考虑了粉尘的健康效应、接触情况及防护措施,对粉尘所得的职业健康风险结果更为全面、准确。
     

Tuberculosis in Bissau: incidence and risk factors in an urban community in sub-Saharan Africa

BACKGROUND: Despite the long history of tuberculosis (TB) research, population-based studies from developing countries are rare. METHODS: In a prospective community study in Bissau, the capital of Guinea-Bissau, we assessed the impact of demographic, socioeconomic and cultural risk factors on active TB. A surveillance system in four districts of the capital identified 247 adult (>or=15 years) cases of intrathoracic TB between May 1996 and June 1998. Risk factors were evaluated comparing cases with the 25,189 adults living in the area in May 1997. RESULTS: The incidence of intrathoracic TB in the adult population was 471 per 100 000 person-years. Significant risk factors in a multivariate analysis were increasing age (P < 0.0001), male sex (odds ratio [OR] = 2.58, 95% CI: 1.85, 3.60), ethnic group other than the largest group (Pepel) (OR = 1.64, 95% CI: 1.20, 2.22), adult crowding (OR = 1.68, 95% CI: 1.18, 2.39 for >2 adults in household), and poor quality of housing (OR = 1.66, 95% CI: 1.24, 2.22). Household type was important; adults living alone or with adults of their own sex only, had a higher risk of developing TB than households with husband and wife present, the adjusted OR being 1.76 (95% CI: 1.11, 2.78) for male households and 3.80 (95% CI: 1.69, 8.56) for female households. In a multivariate analysis excluding household type, child crowding was a protective factor, the OR being 0.68 (95% CI: 0.51, 0.90) for households with >2 children per household. CONCLUSIONS: Bissau has a very high incidence of intrathoracic TB. Human immunodeficiency virus (HIV), increasing age, male sex, ethnicity, adult crowding, family structure, and poor housing conditions were independent risk factors for TB. Apart from HIV prevention, TB control programmes need to emphasize risk factors such as socioeconomic inequality, ethnic differences, crowding, and gender.     

Pesticide risk assessment in a lagoon ecosystem. Part I: exposure assessment

This work is the first step of a research project on pesticide risk assessment for a coastal lagoon ecosystem (Orbetello lagoon, central Italy). Pesticide exposure was evaluated by means of predictive and experimental approaches. Predicted environmental concentrations (PECs) for water and sediments were estimated using fugacity-based multimedia models. Pesticide loads were quantified through a study of the use to which agricultural land was put in the study area. Multimedia fate models were used to predict the environmental concentration of 29 active ingredients (mainly insecticides and herbicides) selected among the most widely used within the catchment basin. Worst-case environmental scenarios were developed for the application of these models, in agreement with the precautionary principle. Experimental monitoring was performed on 10 selected chemicals. To assess the value and limitations of predictive and experimental approaches, calculated PECs and monitoring results were compared and discussed. Combined modeling and monitoring approaches have been found to be the best way to date to assess proper exposure.     

Personal and home 222Rn and gamma-ray exposure measured in 52 dwellings

A personal 222Rn and gamma-ray detector has been developed. The detector precision is limited only by the Poisson counting error and has a lower limit of detection in this study of 4.5 kBq m-3 h (4 pCi L-1 day). The detector was used in a study of 52 homes in Illinois to measure the personal exposure vs. the simultaneous exposure on all levels of the home. The ratio of personal exposure to basement 222Rn concentration averaged 0.22, with a high degree of scatter (R2 = 31%). The ratio of personal exposure to first floor 222Rn concentration was 0.71, with good correlation (R2 = 85%). In the absence of personal monitoring data, the best estimate of personal exposure appears to be from measurements in the first-floor living space of the home.     

Current and future risks of asbestos exposure in the Australian community

Background: Australia mined asbestos for more than 100 years and manufactured and imported asbestos products. There is a legacy of in situ asbestos throughout the built environment.

Methods: The aim of this study was to identify the possible sources of current and future asbestos exposure from the built environment. Telephone interviews with environmental health officers, asbestos removalists, and asbestos assessors in Australia sought information about common asbestos scenarios encountered.

Results: There is a considerable amount of asbestos remaining in situ in the Australian built environment. Potential current and future sources of asbestos exposure to the public are from asbestos-containing roofs and fences, unsafe asbestos removal practices, do-it-yourself home renovations and illegal dumping.

Conclusion: This research has highlighted a need for consistent approaches in the regulation and enforcement of safe practices for the management and removal of asbestos to ensure that in situ asbestos in the built environment is managed appropriately.     

Personal carbon monoxide exposure levels: contribution of local sources to exposures and microenvironment concentrations in Milan

In the framework of the EXPOLIS study in Milan, Italy, 48-h carbon monoxide (CO) exposures of 50 office workers were monitored over a 1-year period. In this work, the exposures were assessed for different averaging times and were compared with simultaneous ambient fixed-site concentrations. The effect of gas cooking and smoking and different methods of commuting on the microenvironment and exposure levels of CO were investigated. During the sampling the subjects completed a time-microenvironment-activity diary differentiating 11 microenvironments and three exposure influencing activities: gas cooking, smoking and commuting. After sampling, all exposure and time allocation data were stored in a relational database that is used in data analyses. Ambient 48-h and maximum 8-h distributions were similar compared to the respective personal exposures. The maximum 1-h personal exposures were much higher than the maximum 8-h exposures. The maximum 1-h exposures were as well higher than the corresponding ambient distribution. These findings indicate that high short-term exposures were not reflected in ambient monitoring data nor by long-term exposures. When gas cooking or smoking was present, the indoor levels at "home-" and in "other indoor" microenvironments were higher than without their presence. Compared with ambient data, the latter source was the most affective to increase the indoor levels. Exposure during commuting was higher than in all other microenvironments; the highest daily exposure contribution was found during "car/taxi" driving. Most of the CO exposure is acquired in indoor microenvironments. For the indoor microenvironments, ambient CO was the weakest predictor for "home indoor" concentrations, where the subjects spent most of their time, and the strongest for "other indoor" concentrations, where the smallest fraction of the time was spent. Of the main indoor sources, gas cooking, on average, significantly raised the indoor exposure concentrations for 45 min and tobacco smoking for 30 min. The highest exposure levels were experienced in street commuting. Personal exposures were well predicted, but 1-h maximum personal exposures were poorly predicted, by respective ambient air quality data. By the use of time-activity diaries, ETS exposure at the workplaces were probably misclassified due to differences in awareness to tobacco smoke between smokers and nonsmokers.     

Personal air sampling and risks of inhalation exposure during atrazine application in Honduras

Purpose

To assess occupational inhalation exposure to the herbicide atrazine during pesticide application in a developing country.

Methods

Personal air samples were collected during atrazine application using a personal sampling pump equipped with an OSHA Versatile Sampler (OVS-2) sorbent tube. Samples were collected from 24 pesticide applicators in Honduras. Application was observed during sampling, and a survey was completed in the home.

Results

Fourteen of the 24 participants used pump backpack sprayers to apply atrazine and 10 used tractor/boom systems. Despite applying about 15 times as much atrazine, the tractor/boom participants (11.5 μg/m³) had only slightly higher (not statistically significant) time-weighted averages (TWA) than participants using backpack sprayers (9.6 μg/m³). Within the backpack sprayer group, those that used a cone spray nozzle (11.54 μg/m³) had nearly double the TWA than applicators using a flat spray nozzle (5.98 μg/m³; P = 0.04). In the tractor/boom group, the participants that rode on the boom or the back of the tractor monitoring nozzles (15.0 μg/m³) had almost double the average TWA than tractor drivers (8.0 μg/m³; P = 0.097).

Conclusions

Since tractor/boom pesticide application decreases the number of man-hours required to apply pesticides, and does not increase inhalation exposure significantly, it decreases the overall population occupational exposure. Monitoring nozzles on booms from a distance rather than on the back of a tractor or boom may decrease or eliminate inhalation exposure. Use of flat spray nozzles for herbicide application among pump backpack sprayers may reduce their inhalation exposure.     

Occupational asthma risk from exposures to toluene diisocyanate: A review and risk assessment

Background

Toluene Diisocyanate (TDI) is a known respiratory sensitizer linked to occupational asthma (OA). To better manage worker risks, an appropriate characterization of the TDI‐OA dose‐risk relationship is needed.

Methods

The literature was reviewed for data suitable for dose‐response modeling. Previous study data were fit to models to derive prospective occupational exposure limits (OELs), using benchmark dose (BMD) and low‐dose extrapolation approaches.

Results

Data on eight TDI‐exposed populations were suitable for analysis. There were 118 OA cases in a population contributing 13 590 person‐years. The BMD‐based OEL was 0.4 ppb. The OEL based on low‐dose extrapolation to working lifetime extra risk of 1/1000 was 0.3 ppb.

Conclusions

This study synthesized epidemiologic data to characterize the TDI‐OA dose‐risk relationship. This approach yielded prospective OEL estimates below recent recommendations by the American Conference of Governmental Industrial Hygienists, but given significant study limitations, this should be interpreted with caution. Confirmatory research is needed.