Occupational lead poisoning in the United States: clinical and biochemical findings related to blood lead levels.

Dose-response relationships between blood lead levels and toxic effects have been evaluated in 160 lead workers in two smelters and a chemicals plant. Blood lead levels ranged from 0.77 to 13.51 mumol/litre (16-280 microgram/dl). Clinical evidence of toxic exposure was found in 70 workers (44%), including colic in 33, wrist or ankle extensor muscle weakness in 12, anaemia (Hgb less than 8.69 mumol/litre (Hb/4) or 14.0 gm/dl) in 27, elevated blood urea nitrogen (greater than or equal to 7.14 mmol/litre or 20 mg/dl) in 28, and possible encephalopathy in two. No toxicity was detected at blood lead levels below 1.93 mumol/litre (40 microgram/dl). However, 13% of workers with blood lead levels of 1.93 to 3.81 mumol/litre (40-79 microgram/dl) had extensor muscle weakness or gastrointestinal symptoms. Anaemia was found in 5% of workers with lead levels of 1.93-2.85 mumol/litre (40-59 microgram/dl), in 14% with levels of 2.90 to 3.81 mumol/litre (60-79 microgram/dl), and in 36% with levels greater than or equal to 3.86 mumol/litre (80 microgram/dl). Elevated blood urea nitrogen occurred in long-term lead workers. All but three workers with increased blood urea nitrogen had at least four years occupational lead exposure, and nine had received oral chelation; eight of this group had reduced creatinine clearance, and eight had decreased renal concentrating ability. These data support the establishment of a permissible biological limit for blood lead at a level between 1.93 and 2.90 mumol/litre (40-60 microgram/dl).     

Deaths related to lead poisoning in the United States, 1979-1998

This study was conducted to describe trends in US lead poisoning-related deaths between 1979 and 1998. The predictive value of relevant ICD-9 codes was also evaluated. Multiple cause-of-death files were searched for records containing relevant ICD-9 codes, and underlying causes and demographic characteristics were assessed. For 1979-1988, death certificates were reviewed; lead source information was abstracted and accuracy of coding was determined. An estimated 200 lead poisoning-related deaths occurred from 1979 to 1998. Most were among males (74%), Blacks (67%), adults of age >/=45 years (76%), and Southerners (70%). The death rate was significantly lower in more recent years. An alcohol-related code was a contributing cause for 28% of adults. Only three of nine ICD-9 codes for lead poisoning were highly predictive of lead poisoning-related deaths. In conclusion, lead poisoning-related death rates have dropped dramatically since earlier decades and are continuing to decline. However, the findings imply that moonshine ingestion remains a source of high-dose lead exposure in adults.     

A population-based study of blood lead levels in relation to depression in the United States

Purpose  

Lead is a known neurotoxicant. Several studies have suggested that occupational exposure to lead may lead to depression, anxiety and other psychiatric illness, but few studies have examined environmental lead exposure and depression. We evaluated the relationship between blood lead levels (BLL) and depression in a sample representative of the US population.     

Moderate lead poisoning: trends in blood lead levels in unchelated children.

The appropriate clinical management of children who are moderately poisoned with lead (Pb) is under active investigation. To determine the pattern of change in blood Pb (BPb) levels in the absence of chelation therapy, we followed moderately Pb-poisoned children (initial blood Pb levels 1.21-2.66 mumol/l or 25-55 micrograms/dl) for 6 months with repeated BPb level measurements. Chelation therapy was not administered because all the children had negative lead mobilization tests indicating limited response to the chelating agent, calcium disodium edetate (CaNa2EDTA). Eligible children received the following interventions: notification of the health department to remediate lead hazards; reinforced educational efforts about the toxicity sources and treatment of Pb during 10 clinic and 3 home visits; and iron therapy for children with ferritin levels less than 16 micrograms/l. To quantify the lead paint hazards in the home, we combined a visual rating of the surfaces (intact to peeling) with an X-ray fluorescence (XRF) measurement of the lead content of the painted surface. The sum of these assessments is termed the home environmental score (HES). Data were analyzed from 79 children. BPb levels declined by 27%, on average, over 6 months. HES was correlated with BPb at enrollment, but neither the initial nor later HES measurements predicted BPb at other time points. The HES was highest at enrollment and declined by 50% and 75% at the second and third home visits, respectively. However, only a minority of the children (20%) achieved an HES of 0, indicating no lead paint hazards at home. Despite some ongoing Pb exposure, a parallel fall in BPb levels was observed in subgroups of children with either initially low or high HES (above or below the median HES of 37). Iron status did not account for the change in BPb levels. These data provide evidence that our measure, the HES, is quantifiably related to BPb levels in children, that this correlation is significant only prior to intervention; and that BPb levels decline in children who are moderately poisoned with Pb after they are enrolled in a comprehensive intervention program, even in the absence of chelation therapy and in the presence of ongoing lead paint exposure and Fe deficiency.     

Binational study of pediatric blood lead levels along the United States/Mexico border

To evaluate lead exposure among children living in border communities, the states of Arizona and New Mexico in the United States (US), and the states of Sonora and Chihuahua in Mexico collaboratively requested that the Centers for Disease Control and Prevention (CDC) provide technical assistance to document pediatric blood lead levels (BLLs) in children living along this part of the US/Mexico border. Two studies were conducted to evaluate BLLs of children aged 1-6 years. In 1998, 1210 children were tested in the Arizona/Sonora study; in 1999, 874 children were tested in New Mexico/Chihuahua. Overall geometric mean BLL was 32.5 microg/l (95% Confidence Interval 31.5-33.5) with BLLs ranging from below limit of detection to 320.0 microg/l. Mean BLLs were higher among children living on the Mexican side of the border (43.2 microg/l) compared to those on the US side (22.3 microg/l). Mean BLLs ranged from 14.9 to 31.2 microg/l at the US sites and from 26.9 to 55.2 microg/l at the Mexican sites. This study used a convenience sample and cannot be considered representative of the general population. Nonetheless, the range of mean BLLs among the sites and especially the higher mean BLLs among children living in the border communities in Mexico suggests different exposures to lead and warrants further attention.     

Demographic and socioeconomic factors associated with blood lead levels among Mexican-American children and adolescents in the United States

OBJECTIVE: This study was designed to assess demographic and socioeconomic differences in blood lead levels (BLLs) among Mexican-American children and adolescents in the United States. METHODS: We analyzed data from the Third National Health and Nutrition Examination Survey, 1988-1994, for 3,325 Mexican-American youth aged 1 to 17 years. The main study outcome measures included a continuous measure (microg/dL) of BLL and two dichotomous measures of BLL (> or =5 microg/dL and > or =10 microg/dL). RESULTS: The mean BLL among Mexican-American children in the United States was 3.45 microg/dL (95% confidence interval [CI] 3.07, 3.87); 20% had BLL > or =5 microg/dL (95% CI 15%, 24%); and 4% had BLL > or =10 microg/dL (95% CI 2%, 6%). In multivariate analyses, gender, age, generational status, home language, family income, education of head of household, age of housing, and source of drinking water were statistically significant independent predictors (p<0.05) of having higher BLLs and of having BLL > or =5 microg/dL, whereas age, family income, housing age, and source of drinking water were significant predictors (p<0.05) of having BLL > or =10 microg/dL. CONCLUSIONS: Significant differences in the risk of having elevated BLLs exist among Mexican-American youth. Those at greatest risk should be prioritized for lead screening and lead exposure abatement interventions.     

The relationship between blood lead levels and periodontal bone loss in the United States, 1988-1994

An association between bone disease and bone lead has been reported. Studies have suggested that lead stored in bone may adversely affect bone mineral metabolism and blood lead (PbB) levels. However, the relationship between PbB levels and bone loss attributed to periodontal disease has never been reported. In this study we examined the relationship between clinical parameters that characterize bone loss due to periodontal disease and PbB levels in the U.S. population. We used data from the Third National Health and Nutritional Examination Survey (NHANES III), 1988-1994, for the analyses. A total of 10,033 participants 20-69 years of age who completed a periodontal examination and had whole blood tested for lead were examined. Four types of periodontal disease measures were used to indicate oral bone loss: periodontal pocket depth, attachment loss extent, attachment loss severity, and the presence of dental furcations. We found that dental furcations were the best periodontal bone loss indicator for PbB levels (p = 0.005) in a multivariate linear regression model adjusting for sex, age, race/ethnicity, educational attainment, poverty status, smoking, and age of home. Furthermore, after additional modeling, we found a smoking and dental furcation interaction (p = 0.034). Subsequent stratified analyses indicated that current and past smoking is an effect modifier for dental furcations on PbB levels. These findings indicate that increased PbB levels may be associated with advanced periodontal bone loss, particularly among people with a history of smoking.     

职业性亚急性铅中毒1例报告

1病例介绍患者,女,25岁,系个体蓄电池厂切片工,于2003年10月10日～11月17日接触铅尘作业。车间面积约20m^2,高3m,平时门窗可开启。空气中铅尘浓度大,自然通风差,无通风设备。工人偶而戴防尘口罩,每天工作9h,最多时达11．5h,且卫生习惯差,有时在车间进食。同工种有类似发病者,其车间铅浓度未检测。     

铅对儿童甲状腺功能影响的研究

【目的】本文主要探讨铅中毒对儿童甲状腺功能的影响。【方法】入选对象为0~6岁的儿童,血铅采用钨舟原子吸收光谱法测定,并根据血铅的水平<100μg/L,100~200μg/L,200~499μg/L将儿童分为正常血铅组、轻度铅中毒组和中度铅中毒组。对三组对象均采用化学发光免疫技术,分别测其TT3、TT4、FT3、FT4、TSH共5项甲状腺功能指标,并计算出FT4/TSH的比值,将三组甲状腺功能指标和FT4/TSH的比值进行方差分析。【结果】正常血铅组、轻度铅中毒组和中度铅中毒组TT3、TT4、FT3、FT4值差异均无显著性,而三组的TSH值,FT4/TSH比值存在显著性差异。【结论】虽然未达到甲状腺功能低下的程度,但是轻中度铅中毒对儿童甲状腺功能已存在影响;并且随着血中铅浓度的增高,甲状腺功能损害的程度也会加重。     

Occupational and environmental medicine in the United States

The history and the current status of occupational and environmental medicine (OEM) research, educational resources, clinical practice patterns, and regulatory framework in the United States are reviewed. Current or anticipated changes in health-care financing, clinical practice patterns, occupational safety and health regulations and enforcement, and funding for research and medical education at the national level are already having an impact on OEM activities in this country. Received: 8 October 1997 / Accepted: 16 October 1997     

Occupational exposure to lindane: clinical and laboratory findings

Czeglédi-Jankó, G., and Avar, P. (1970).Brit. J. industr. Med.,27, 283-286. Occupational exposure to lindane: clinical and laboratory findings. Workers exposed to lindane for up to two years have been observed clinically, with EEGs and by chemical analysis of whole blood for lindane. In workers with mild but definite symptoms, the concentrations of lindane in whole blood were likely to be greater than 0·02 ppm, a value close to the upper values in members of the general population in Hungary.     

Occupational exposure to aldrin: clinical and laboratory findings

Avar, P., and Czeglédi-Jankó, G. (1970).Brit. J. industr. Med.,27, 279-282. Occupational exposure to aldrin: clinical and laboratory findings. The paper reports the relation of neurological symptoms and EEG findings to the concentration of HEOD in whole blood. Fifteen men who had been making aldrin in a fertilizer plant for up to five years were examined in the last month of exposure. Three of them were followed up for seven months after cessation of exposure. Eight were examined on one occasion two years after their last period of exposure to aldrin.

Some men in whom the HEOD concentrations in whole blood were above 0·10 ppm had symptoms of poisoning but these were absent in others with higher (0·25 ppm) concentrations. In three men severely affected at the time of cessation of exposure, symptoms ceased within seven months. Symptoms that were still present in others two years later are ascribed to occupational exposure to lindane.

After cessation of exposure, the concentration of HEOD in whole blood fell slowly, initially at a rate corresponding to a biological half-life of 50 to 150 days. Later, it fell more slowly, so that two years after the cessation of exposure the concentrations of HEOD in whole blood were still higher than in the general Hungarian population.

     

Occupational health nursing in the United States

This article is a summary of information about occupational health nurses and occupational health nursing in the United States. The article provides demographic, education, credentialing, role, and other data based on secondary analysis of occupational health nurses' responses to the 2008 National Sample Survey of Registered Nurses. Current issues affecting the U.S. work force and businesses are addressed and high-risk business and industrial sectors are noted. Occupational health nurse practice opportunities are highlighted and practice areas where occupational health nursing research is currently focused are discussed. The article also examines the challenges facing the next generation of occupational health nurses.     

婴幼儿血铅水平及其影响因素

目的　了解婴幼儿的血铅水平及其影响因素。　方法　用石墨炉原子吸收光谱法测定2 6 2例婴幼儿末梢血铅浓度 ,并进行铅中毒影响因素的调查。　结果　婴幼儿血铅算术平均值为0 .4 3μmol/L,范围为 0 .10～ 1.4 5 μmol/L,铅中毒发生率为 37.0 2 % (97/2 6 2 )。不同性别、不同年龄婴幼儿血铅水平及铅中毒发生率差异无显著性 (P>0 .0 5 ) ,各年龄婴幼儿血铅等级分布以 I级最高 ,婴幼儿铅中毒属 II～ III级。饭前不洗手、经常在马路边玩耍、经常看彩色书刊后不洗手、父母职业、住房为 1990年以后建造的是影响婴幼儿血铅水平的因素。　结论　婴幼儿已受到不同程度的铅损伤 ,应引起家长及有关方面的重视