Low-level Eexposure to lead dust in unusual work schedules and hematologic, renal, and hepatic parameters.

BACKGROUND: Many workers are exposed to lead dust in lead-­zinc mines. Exposure to this heavy toxic metal and its compounds can cause irreversible adverse health effects. OBJECTIVE: To assess possible hematotoxic, nephrotoxic, and hepatotoxic potentials of low levels of lead in a group of mine workers exposed to this heavy metal in an unusual work schedule. METHODS: A total of 73 exposed and 70 non-exposed employees were interviewed. Demographic data, and occupational and medical history of the employees were obtained by questionnaires. Air monitoring was performed to determine the workers' time-weighted average (TWA) exposure to lead dust. The threshold limit value (TLV) for lead was adjusted for unusual work schedules according to the model developed by the University of Montreal and the Institute de Recherche en Sante et en Securite du Travail (IRSST). Blood samples were collected for complete blood count, liver and kidney function tests. Data were analyzed using version 21.0 of the SPSS software. RESULTS: The TWA exposure of workers was 24 µg/m3. On average, the worker's exposure to lead dust did not exceed the 8-h OSHA and ACGIH TLV-TWA of 50 µg/m3. Significant associations were found only between exposure to lead and platelet count, red cell distribution width, total protein, and albumin. CONCLUSIONS: Exposure to low levels of lead dust in unusual work schedules was not associated with overt hematotoxicity, hepatotoxicity or nephrotoxicity. However, mild, sub-clinical, pre-pathologic significant changes were noted in some blood parameters of the exposed employees as compared with their referent counterparts.

Improving human health outcomes with a low-cost intervention to reduce exposures from lead acid battery recycling: Dong Mai, Vietnam.

This study details the first comprehensive evaluation of the efficacy of a soil lead mitigation project in Dong Mai village, Vietnam. The village's population had been subject to severe lead poisoning for at least a decade as a result of informal Used Lead Acid Battery (ULAB) recycling. Between July 2013 to February 2015, Pure Earth and the Centre for Environment and Community Development (Hanoi, Vietnam) implemented a multi-faceted environmental and human health intervention. The intervention consisted of a series of institutional and low-cost engineering controls including the capping of lead contaminated surface soils, cleaning of home interiors, an education campaign and the construction of a work-clothes changing and bathing facility. The mitigation project resulted in substantial declines in human and environmental lead levels. Remediated home yard and garden areas decreased from an average surface soil concentration of 3940mg/kg to <100mg/kg. One year after the intervention, blood lead levels in children (<6 years old) were reduced by an average of 67%-from a median of 40.4µg/dL to 13.3µg/dL. The Dong Mai project resulted in significantly decreased environmental and biological lead levels demonstrating that low-cost, rapid and well-coordinated interventions could be readily applied elsewhere to significantly reduce preventable human health harm.

United States house dust Pb concentrations are influenced by soil, paint, and house age: insights from a national survey.

BACKGROUND: Lead (Pb) in house dust contributes significantly to blood lead levels (BLLs) in children which may result in dire health consequences. Assessment of house dust Pb in the United States, relationships with Pb in soil and paint, and residential factors influencing Pb concentrations are essential to probing drivers of house dust Pb exposure. OBJECTIVE: Pb concentrations in vacuum-collected house dust are characterized across 346 homes participating in the American Health Homes Survey II (AHHS II), a US survey (2018-2019) evaluating residential Pb hazards. Connections between house dust Pb and soil Pb, paint Pb, and other residential factors are evaluated, and dust Pb concentration data are compared to paired loading data to understand Pb hazard standard implications. RESULTS: Mean and median vacuum dust Pb concentrations were 124 µg Pb g-1 and 34 µg Pb g-1, respectively. Vacuum-collected dust concentrations and dust wipe Pb loading rates were significantly correlated within homes (α < 0.001; r ≥ 0.4). At least one wipe sample exceeded current house dust Pb loading hazard standards (10 µg ft-2 or 100 µg Pb ft-2 for floors and windowsills, respectively) in 75 of 346 homes (22%). House dust Pb concentrations were correlated with soil Pb (r = 0.64) and Pb paint (r = 0.57). Soil Pb and paint Pb were also correlated (r = 0.6). IMPACT: The AHHS II provides a window into the current state of Pb in and around residences. We evaluated the relationship between house dust Pb concentrations and two common residential Pb sources: soil and Pb-based paint. Here, we identify relationships between Pb concentrations from vacuum-collected dust and paired Pb wipe loading data, enabling dust Pb concentrations to be evaluated in the context of hazard standards. This relationship, along with direct ties to Pb in soil and interior/exterior paint, provides a comprehensive assessment of dust Pb for US homes, crucial for formulating effective strategies to mitigate Pb exposure risks in households.

A County-Level Program for the Evaluation of the Potential for Take-Home Lead Exposures Among Children in Michigan.

OBJECTIVE: Take-home lead exposure involves lead dust inadvertently carried from the worksite by employees that becomes deposited in their homes and vehicles. We piloted a program in 2 counties in Michigan to investigate the countywide potential for take-home lead exposures across industries. METHODS: During 2018-2020, we identified establishments through internet searches and industry-specific registries. We visited establishments with a physical storefront in-person; we attempted to contact the remaining establishments via telephone. We administered questionnaires at the establishment level to assess the presence of lead and the current use of practices meant to mitigate the potential for take-home lead exposures. We recruited workers for wipe sampling of lead dust from their vehicle floors to test for lead levels. RESULTS: We identified 320 establishments with potential lead use or exposures. Questionnaire responses revealed widespread worker exposures to lead and a lack of education and implementation of best practices to prevent lead from leaving the worksite. Dust samples (n = 60) collected from employee vehicles showed a ubiquitous tracking of lead out of the workplace, with a range of 5.7 to 84 000 µg/ft2 and a geometric mean of 234 µg/ft2. Of the sample results, 95.0% were above the lead dust clearance levels for homes established by the US Environmental Protection Agency. CONCLUSIONS: This work suggests that take-home lead exposures are widespread and may be important sources of lead exposure among children. It also demonstrates the feasibility of a program for the identification of establishments whose employees may be susceptible to taking lead dust home with them and whose children may subsequently be targeted for blood lead monitoring.

Lead exposure in clinical imaging - The elephant in the room.

PURPOSE: Radiation Protection Apparel (RPA) is used during diagnostic imaging and interventional procedures to minimise incidental radiation exposure. The majority of RPA in use are lead-containing, which has until now been considered safe. A recent single-centre study has demonstrated that the external surface of 63 % of RPA was contaminated with lead dust. The purpose of this study was to reproduce this investigation with a larger sample size across Europe and assess whether decontamination procedures were possible. METHOD: The routine RPA Quality Control (QC) process was adapted to include lead dust contamination tests and decontamination if present. The presence of lead dust was determined using a commercially available colorimetric method. RPA that failed initial QC or could not be decontaminated were removed from use. RESULTS: From June to October 2019, 728 RPA from 85 imaging centres from five countries underwent initial QC. Of these, 712 were tested for lead dust contamination which was present on 162 (23 %). Following cleaning, 85 (12 %) remained contaminated and were removed from use. Linear regression analysis shows a significant correlation between type of RPA and contamination, (p = 0.0015). There was no correlation between contamination and imaging department, year of manufacture, country and RPA condition (p-values 0.98, 0.90, 0.94 and 0.14 respectively). CONCLUSIONS: Lead dust contamination is present on 23 % of RPA that would pass routine QC procedures. Approximately half were not amenable to decontamination and were removed from use. Procedures were introduced for the routine handling of RPA, and updated QC steps for assessment and cleaning. Lead-free RPA should be considered.

Dynamic Geochemistry of Tetraethyl Lead Dust during the 20th Century: Getting the Lead In, Out, and Translational Beyond.

This commentary provides a brief overview of policy decisions that permitted getting tetraethyl lead (TEL) into petrol; global geochemical lead-dust deposition evidence; 1975 catalytic converter requirements; concern about habitability of cities; a personal perspective on legacy lead research that accelerated getting TEL out of petrol; and translational beyond, including New Orleans pre- vs. post-Hurricane Katrina observations about legacy lead interventions that effectively improve urban children’s health outcomes.