Changes of nerve excitability and urinary deltamethrin in sprayers

Summary The nerve excitability of median nerve as well as the urinary deltamethrin and its metabolite dibromovinyl-dimethyl-cyclopropane carboxylic acid (Br₂A) were detected in 24 deltamethrin sprayers in an assessment of the exposure and effect of deltamethrin. Twenty-nine male, unexposed referents of the same age range were also selected. The urinary deltamethrin and its metabolite Br₂A were detectable by GC and HPLC in the sprayers after exposure. The nerve excitability detected with an electromyograph and pairs of stimuli at variable intervals showed that there was a prolongation of supernormal period in median nerve of the exposed group after a 3-d spraying compared with that before spraying which became more significant 2 d after cessation of exposure. In the mean time, no change of supernormal period in the median nerve of reference group was found at the 3-d interval. Nearly half of the sprayers had a supernormal period prolonged by more than 4 ms after spraying, whereas nearly none of the reference group showed similar changes after repeated examinations. Although there was neither correlation between the nerve excitability changes and the urinary deltamethrin or Br₂A excretion, nor was a case of acute deltamethrin poisoning diagnosed, the non invasive technique used for nerve excitability detection in this study seems to be valuable in studying deltamethrin toxicity on human.     

Determination of 3,4-dimethylhippuric acid as a biological monitoring index for trimethylbenzene exposure in transfer printing workers

Summary The relationship between exposure to 1,2,4-trimethylbenzene (1,2,4-TMB) and urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA), one of its metabolites, was studied in workers involved in transfer printing. Airborne TMBs were sampled by an organic vapor monitoring badge and analyzed by capillary gas chromatography. Urinary 3,4-DMHA and creatinine were analyzed under the same conditions of high-performance liquid chromatography. The exposure concentration of 1,2,4-TMB among workers was around 25 ppm, the threshold limit value (TLV). The urinary concentration of 3,4-DMHA was low at the start of each shift and high at the end. Exposure to the TLV (25 ppm) of 1,2,4-TMB results in a urinary 3,4-DMHA concentration of 410 mg/g creatinine (r = 0.897, P < 0.001). Urinary 3,4-DMHA concentration could be used as a biological monitoring index for 1,2,4-TMB exposure.     

Biological monitoring of cadmium exposure: reliability of spot urine samples

Summary Concentration-dilution of spot urine samples is a shortcoming of the biological monitoring of industrial xenobiotics. To ascertain whether the adjustment of urinary cadmium measured in spot samples is appropriate, urine samples were taken three times, once a week for 3 successive weeks, from 25 welders employed in the manufacture of jewellery (total 75 samples). Cadmium, creatinine, specific gravity, total urinary solutes, urinary volume and urinary flow rate were measured in 12-h collections and in spot samples taken immediately afterwards. Creatinine and total urinary solutes showed high inverse correlation with urinary flow rate (r = –0.858 and r = –0.768 respectively). Urinary cadmium displayed a similar trend but the correlation was not significant (r = –0.145). Creatinine adjustment of urinary cadmium values in spot samples increased the correlation with the same index in timed samples adjusted for urinary volume (r = –0.808) or urinary flow rate (r = 0.821) compared with non-adjustment (r = 0.732 and r = 0.738, respectively). Creatinine adjustment of spot sample values is also suitable for a wide range of urinary concentrations; discarding excessively diluted or concentrated urines, correlation of urine samples improved for non-adjusted or specific gravity-adjusted values, whereas no changes were observed for creatinine-adjusted values.     

Assessment of long-term styrene exposure: a comparative study of a logbook method and biological monitoring

In a recent joint European research project Biomonitoring of human populations exposed to genotoxic environmental chemicals: biomonitoring of styrene exposed individuals, a logbook method for assessment of long-term styrene exposure was applied in two Danish factories manufacturing glass fibre-reinforced polyester. The method was based on work process identification, assignment of work process concentrations and logbook keeping. Measures of exposure calculated by this method were compared with results from simultaneous measurements of styrene in blood and the metabolites mandelic acid and phenylglyoxylic acid in urine. Correlations were comparable with those obtained by use of personal samplers as published in the literature. Styrene in blood, however, only correlated with logbook concentrations at the time of sampling. Exposures were moderate to low. Mean personal 8-h time-weighted average concentration (8hTWAC) was 76 mg/m³ styrene (SD 54 mg/m³, range 2–230 mg/m³). The Danish 8hTWAC threshold limit value for styrene in air, 105 mg/m³ (25 ppm), was exceeded on 17% of personal days. The summed urinary metabolites, mandelic acid and phenylglyoxylic acid, had a mean personal value of 138 mg/g creatinine (SD 84 mg/g creatinine) on the day of sampling. Blood styrene mean value was 129 g/l (SD 74 g/l, range 66–358 g/l). It is concluded that the logbook method offers a technique for testing whether measurements are performed on representative days and may be recommended as a tool supplementary to biological monitoring in the assessment of long-term exposure.     

Biological monitoring of cobalt exposure,based on cobalt concentrations in blood and urine

Summary Cobalt exposure level and its concentrations in blood and urine were determined for 175 hard metal workers. For control data, the cobalt concentrations in blood and urine were measured for 20 office workers. The exposed workers had significantly higher cobalt concentrations in both blood and urine. The relationships between exposure level and cobalt concentrations in blood and urine were linear and positive. The results clearly showed that the cobalt concentration in the blood or urine can be used as an exposure indicator. With cobalt exposure of 100 g/m³, the cobalt concentration was 0.57 to 0.79 g/dl in blood and 59 to 78 g/l in urine with 95% confidence limits. In workers using respirators, the cobalt concentrations in the blood and urine decreased to 2/5 and 1/8, respectively, of those not using respirators.     

贝类产品中溴氰菊酯残留量的测定

目的：通过对样品前处理方法的研究比较,建立贝类产品中溴氰菊酯残留量的气相色谱检测方法。方法：样品用乙腈提取,石油醚去除脂肪等杂质,Florisil硅土柱净化,V（乙酸乙酯）：V（石油醚）=1：4洗脱,浓缩后经气相色谱-电子捕获检测器（GC-ECD）检测,外标法定量。结果：利用该方法,能有效去除杂质、色素,平均回收率为78.0%～95.2%,相对标准偏差（RSD）为5.32%～10.44%,最低检测限为0.5μg/kg。结论：该方法操作简便,灵敏度高,重现性好,能满足贝类中溴氰菊酯低残留检测的要求。     

江汉平原部分地区媒介按蚊对溴氰菊酯抗性监测分析

目的了解媒介按蚊对溴氰菊酯抗性,为合理使用杀虫剂提供科学依据。方法采用WHO成蚊滤纸接触法,观察首只蚊虫击倒时间、击倒率和死亡率,以区分剂量判定抗性级别,以开始击倒时间和击倒率评估Kdr抗性。结果江汉平原区媒介按蚊首只被溴氰菊酯击倒时间为6～25 min,接触60 min击倒率为1.00%～9.62%,KT50为1 003.5～24 099.78 min,抗性指数4.41～105.79,观察24 h死亡率为2.00%～8.65%,为高抗性群体。结论江汉平原按蚊对溴氰菊酯已产生高度抗性,应交替使用不同类型卫生杀虫剂,确保防治效果,延缓蚊虫抗性升级。     

硝苯地平对溴氰菊酯中毒豚鼠心血管毒性的拮抗作用

目的 探讨钙离子通道阻滞剂－硝苯地平对溴氰菊酯（DM）心血管毒性的拮抗作用。方法 应用生理多导记录仪观察DM染毒及硝苯地平给药后豚鼠2h内心血管功能的变化。结果 豚鼠一次性腹腔注射DM25mg/kg,其收缩压、舒张压和心肌最大收缩速率（dp/dtmax^ )值分别在15、90和30min后明显升高,与染毒前即刻（0min）相比差异有显著性（P＜0．05）;中毒豚鼠心电图表现为：（1）心率减慢,30min后降至平台期;（2）在观察时间内QRS间期持续性延长;（3）QT比值（QTr）增大,15min后增至平台期;（4）心律失常发生率为50％,主要表现为房室传导阻滞和室性早搏。以硝苯地平治疗后,中毒豚鼠的上述心血管功能指标与染毒前即刻相比未见明显改变。结论 硝苯地平对DM中毒豚鼠的心血管毒性具有拮抗作用。     

Biological monitoring for exposure assessment of volatile organic compounds by Korean firefighters at the fire site

The VOCs and metabolites in urine for exposed VOCs were evaluated for firefighters who participated in the actual fire fighting to determine whether firefighters were exposed to hazardous chemicals, which is the basic data on cancer risk of firefighters. When the fire extinguishing time is long, the concentration of benzene, PHEMA, and toluene among VOCs and metabolites in the case of fire suppression, rescue, and fire investigation work, which is estimated that the exposure of hazardous substances generated from the fire site at the time of fire suppression was large, significantly increased. In the case where the number of urination is 2 or less, the concentration of TZCA, toluene, and benzene among VOCs and metabolites was significantly increased compared to the number of urinating more than 2 times. In the concentration of VOCs and metabolites in urine corrected with creatinine, the concentrations of toluene and PHEMA in urine were significantly higher. The concentration of PHEMA in urine was higher in the group who participated in the fire suppression for more than 11 hours (long time) than the group who participated in the fire suppression for a short time.     

Biological monitoring of persons exposed to methanol vapours

Summary Five volunteers were exposed to constant and suitably graded concentrations of methanol vapours for a period of 8 h. The retention of methanol in the lungs and the course of its excretion in urine were monitored at single and at daily repeated exposures.From the concentration in inspired air, lung retention, minute lung ventilation and duration of exposure, the methanol dose retained in the organism of the experimental subjects was calculated. The dose correlated well with the methanol concentration (mmol/l or mg/1) in whole-shift urine; using other units (mg/l_corr., mg/creat., mg/time) the correlation was unsatisfactory.An exposure test was proposed which permits the estimation of the retained methanol dose on the basis, of an analysis of whole-shift urine. The test yields good results even if the subjects perform physical work and consequently have enhanced lung ventilation, or in cases where the air besides methanol contains vapours of other organic solvents (ethanol, acetone). The results may be burdened by a certain error if the methanol concentration in air fluctuates extremely, or if exposure is interrupted by breaks. Nonetheless even in such circumstances the test provides valuable information on the level of occupational exposure to methanol.     

普乐林对溴氰菊酯中毒豚鼠心血管毒性的保护作用

目的　探讨溴氰菊酯的心血管毒性及普乐林的保护作用。方法　将豚鼠随机分成溴氰菊酯染毒组、普乐林治疗组以及芝麻油对照组, 应用生理多导记录仪研究其心血管功能的变化。结果　溴氰菊酯染毒后豚鼠血压升高、收缩力加强和心率减慢; 心电图表现为ＱＴｒ 增大、ＱＲＳ 间期延长、ＳＴ 段压低、Ｔ 波加深以及多种心律失常。经普乐林治疗后中毒豚鼠除ＱＴｒ 仍一时性增加外, 其它心血管功能未见明显改变。结论　普乐林对溴氰菊酯中毒豚鼠的心血管毒性具有保护作用。     

溴氰菊酯对成年大鼠睾丸组织的毒性作用

目的为研究溴氰菊酯(deltamethrin,DM)对成年大鼠睾丸组织的毒性作用。方法将60只成年大鼠随机分为5组,即对照(玉米油)组和2.1、4.375、8.75、17.5 mg/kg DM染毒组,每组12只,连续灌胃染毒15 d。测定大鼠每日生精量和雄激素受体(AR)磷酸化蛋白水平,观察睾丸形态的变化。结果与对照组比较,8.75、17.5 mg/kg溴氰菊酯染毒组大鼠睾丸每日生精量均下降;各剂量溴氰菊酯染毒组大鼠睾丸组织中磷酸化AR蛋白表达水平和萎缩生精小管数均较高,生精小管数均减少,生精小管周长均缩短,差异有统计学意义(P0.05)。且随着溴氰菊酯染毒剂量的升高,大鼠睾丸每日生精量、生精小管数和生精小管周长呈逐渐下降的趋势,睾丸组织中磷酸化AR蛋白表达水平和萎缩生精小管数均呈上升趋势。结论 DM可通过提高AR磷酸化水平来抑制AR的活性,导致大鼠睾丸组织损伤及生精能力下降。     

Biological monitoring of acrylonitrile exposure

A study was made of the excretion pattern of acrylonitrile (AN) in urine of 15 AN-exposed workers. During a 7-day working period with the following 2 days off, the workers delivered all their urines separately. Exposure data, collected by personal monitoring, showed a mean 8-hour TWA value of 0.13 ppm. The excretion of AN in urine (AN(U)) showed a typical pattern; concentrations peaked at the end or shortly after the end of the workday and decreased rapidly until the beginning of the next workday. A control group of 41 nonexposed workers of the same company showed a significant increase of AN(U) with increasing number of cigarettes smoked. The AN(U) concentrations of the exposed workers however were, despite the low exposure, much higher than those of the controls, both during the workdays and during the days off. Biological monitoring of AN-exposed workers by assessing AN(U) therefore seems a very sensitive exposure evaluation method, especially because it accounts for inhalation as well as skin penetration as routes for entering the body.     

溴氰菊酯对大鼠仔代神经行为发育的影响

目的观察溴氰菊酯(deltamethrin,DM)对孕期雌性大鼠仔代神经行为发育的影响.方法将妊娠大鼠随机分为对照组和两个剂量组,妊娠第1天～第19天隔日1次经口染毒,剂量分别为0、3.35和6.70 mg/kg,观察其自然分娩后仔代生长发育状态及神经行为功能.结果6.70 mg/kg DM染毒组仔鼠出生体重为(5.02±0.36)g,低于对照组[(5.50±0.24)g];出生存活率为91.94%、哺育存活率为83.87%,均低于对照组(100%、100%),差异均有显著性(P＜0.05).仔鼠张耳、体毛长出及睁眼时间的差异则未见显著性(P＞0.05).6.70 mg/kg DM染毒组仔鼠地面翻正反射阳性出现时间为(6.1±0.3)d、空中翻正反射阳性出现时间为(17.4±1.2)d,与对照组[(5.5±0.3)d、(16.2±1.6)d]相比,差异有显著性(P＜0.01);延迟时间为(3.86±1.40)s、被动逃避反应阳性率为24%,与对照组[(1.68±0.70)s、6%]相比,差异有显著性(P＜0.05).两个剂量DM染毒组仔鼠旷场试验中行进格子数均明显降低,与对照组的差异均有显著性(P＜0.05).结论母鼠孕期接触DM可引起其仔代生长发育及神经行为发育迟缓.     

江苏省部分地区中华按蚊对溴氰菊酯和氟氯氰菊酯的敏感性调查

目的了解江苏省部分疟区中华按蚊对溴氰菊酯和氟氯氰菊酯的敏感性。方法采用WHO推荐的接触筒强迫接触法,观察接触10、15、20、30、40、50、60min的蚊虫击倒数和24h后的死亡率。结果盱眙、泗洪、睢宁、宜兴4个县（市）中华按蚊接触0．05％溴氰菊酯60min时的击倒率分别为67．37％、64．00％、71．43％和78．40％,24h后的死亡率分别为68．42％、68．00％、72．53％和76．80％,4个县（市）的中华按蚊对溴氰菊酯的抗性评价均为R级。盱眙、泗洪、睢宁、宜兴4个县（市）中华按蚊接触0．15％氟氯氰菊酯60min时的击倒率分别为84．13％、91．76％、89．80％和100％,24h后的死亡率分别为85．71％、91．76％、93．88％和100％,宜兴地区的中华按蚊对氟氯氰菊酯抗性评价为S级,其他3个县（市）的中华按蚊对氟氯氰菊酯抗性评价为M级。结论江苏省部分疟区中华按蚊已对溴氰菊酯产生高度抗性,对氟氯氰菊酯已产生初步抗性。今后,在媒介防制上应采取综合治理措施,以防止抗性产生。     

Multiple metals exposure in a small-scale artisanal gold mining community

Urinary metals were characterized in 57 male residents of a small-scale gold mining community in Ghana. Chromium and arsenic exceeded health guideline values for 52% and 34%, respectively, of all participants. About 10–40% of the participants had urinary levels of aluminum, copper, manganese, nickel, selenium, and zinc that fell outside the U.S. reference range. Exposures appear ubiquitous across the community as none of the elements were associated with occupation, age, and diet.     

Biological monitoring of exposure to monochlorobenzene

Summary We assessed the exposure to monochlorobenzene (MBC) of 44 male subjects performing maintenance work in a diphenylmethane-4-4diisocyanate producing plant. In total, 251 whole shift personal air sampling measurements (passive diffusion) were carried out and at the end of the shift, during which the time-weighted average exposure (TWA) to MCB was determined, a urine sample was collected for the analysis of 4-chlorophenol and 4-chlorocatechol, the two main urinary metabolites of MCB in human. The MCB-TWA values were log normally distributed with a median of 1.2 ppm and a range from < 0.05 to 106 ppm. The Pearson's correlation coefficient between the log MCB-TWA (ppm) and the log concentration (mg/g creatinine) of the metabolites in post shift-urine samples amounted to 0.65 (P<0.001) for 4-chlorophenol (log 4-chlorophenol = 0.22 + 0.43 log MCB-TWA) and 0.72 (P<0.001) for 4-chlorocatechol (log 4-chlorocatechol = 0.53 + 0.58 log MCB-TWA), respectively. On the average the workers excreted three times more 4-chlorocatechol than 4-chlorophenol. The follow up of 21 workers over several days did not show any tendency for the metabolite concentration in urine to increase during the workweek.     

Biological monitoring of controlled toluene exposure

Objectives: Widespread exposure to toluene occurs in the printing, painting, automotive, shoemaking, and speaker-manufacturing industries. The relationship between air concentrations and the absorbed dose is confounded by dermal exposure, personal protective devices, movement throughout the workplace, and interindividual differences in toluene uptake and elimination. Methods: To determine the best biological indicator of exposure we examined the blood and alveolar breath concentrations of toluene as well as the urinary excretion rates of hippuric acid and of o-, m-, and p-cresols from 33 controlled human inhalation exposures to 50 ppm for 2 h. Results: Among the metabolites, o-cresol was least influenced by background contributions, whereas the p-cresol and hippuric acid rates were obscured by endogenous and dietary sources. Toluene levels in alveolar breath proved to be the most accurate and noninvasive indicator of the absorbed dose. A physiologic model described blood and breath data using four measured anthropometric parameters and the fit values of extrahepatic metabolism and adipose-tissue blood flow. Conclusions: After breathing rate and extrahepatic metabolism had been set to conservative (protective) values (the 97.5th and 2.5th percentiles, respectively) the model predicted that pre-final-shift breath levels of ≤10 μmol/m³ and post-final-shift levels of ≤150 μmol/m³ corresponded to average workplace exposure levels of ≤50 ppm toluene. Alternately, we used the distributions and covariances of the measured and fit model parameters to yield conservative pre-final-shift levels of ≤7.3 μmol/m³ and post-final-shift breath levels of ≤120 μmol/m³ that were reflective of workplace exposure levels of ≤50 ppm toluene. Received: 30 December 1997 / Accepted: 12 June 1998     

气相色谱法检测大米中溴氰菊酯残留量的测量不确定度评价

目的通过对气相色谱法检测大米中溴氰菊酯残留量的测量不确定度来源的系统分析,提高对大米中溴氰菊酯残留量的检测水平和能力,并找出影响测量结果不确定度的主要因素。方法按照JJF1059．1—2012（GUM）《测量不确定度评定和表示》和《CNAS—CL05：2011》的要求,找出分析不确定度的来源,建立测量模型,计算各不确定度分量,对其进行评定。结果大米中溴氰菊酯农药残留量的测量不确定度由标准曲线拟合、样品前处理后的回收率、标准溶液的逐级稀释、样品结果的重复性、样品称量、标准物质等引入的不确定度各组分合成。测量结果的扩展不确定度按公式U：k×u（合）计算。测定结果报告C=CX±U,以加入溴氰菊酯的标准物质的0．30mg／kg的大米做气相色谱法检测残留量,报告为（0．30±0．0622）mg／kg。结论从气相色谱法检测大米中溴氰菊酯残留量的测量不确定度分量汇总分析可以看出,影响不确定度的因素有很多,而样品的前处理及标准曲线拟合是最为关键的因素。