Lead Exposure and Oxidative Stress in Coal Miners

We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups: three groups according to the number of consecutive working days, and a fourth control group. Miners who worked for three consecutive days had higher blood levels of lead and 8-isoprostane than the control group(P < 0.001). Correlation between lead and 8-isoprostane was of medium strength(r = 0.512, P < 0.001). Short-term lead environmental exposure can potentially harmful and should be considered when formulating improvements in working processes.

Maternal Lead Exposure Induces Down-regulation of Hippocampal Insulin-degrading Enzyme and Nerve Growth Factor Expression in Mouse Pups

Lead exposure is a known potential risk factor for neurodegenerative diseases such as Alzheimer's disease(AD). Exposure to lead during the critical phase of brain development has been linked with mental retardation and hypophrenia in later life. This study was aimed to investigate the effects of lead exposure of pregnant mice on the expressions of insulin-degrading enzyme(IDE) and nerve growth factor(NGF) in the hippocampus of their offspring. Blood samples were collected from the tail vein, and after anesthetizing the pups, the brain was excised on postnatal day 21. Lead concentrations were determined by graphite furnace atomic absorption spectrophotometry, and the expressions of IDE and NGF were determined by immunohistochemistry and Western blotting. Results showed that the reduction in IDE and NGF expression in the hippocampus of pups might be associated with impairment of learning and memory and dementia induced by maternal lead exposure during pregnancy and lactation.

Assessment of Lead Exposures during Abrasive Blasting and Vacuuming in Ventilated Field Containments: A Case Study

Painting contractors have struggled with implementation and assessment of lead exposure controls leading to persistently elevated blood lead levels in this high-risk group of workers. The objective of this study was to assess the intensity of lead exposures based on commonly used air velocities inside field containment structures during abrasive blasting and vacuuming. Exposures were assessed over 14 days from April to July 2021 at a tainter gate and bridge lead paint removal project. Personal air samples, skin wipes, air velocity readings, and blood lead samples were collected. The geometric mean (GM) lead exposure for abrasive blasters and vacuumers was ≥4 × the OSHA Lead Permissible Exposure Limit (PEL) of 50 μg/m3. There was high variability in the personal lead exposures (Geometric standard deviation (GSD) 4.0 - 5.0). The GM hand wipe exposures exceeded a Dermal PEL of 500 μg/wipe (abrasive blaster 564 μg/wipe and vacuumer 754 μg/wipe). Residual lead was measured on workers’ hands in 67% of the post hand washing samples. Air velocities measured inside of the field containments ranged from 107 feet per minute to 229 feet per minute. The effect of air velocity on the concentration of lead on workers’ hands after work (F = 0.58, p = 0.35) and airborne lead concentration was not significant (F = 0.36, p = 0.48). Six of the eight workers’ blood lead levels increased after exposure to lead. There was a non-statistically significant relationship between lead remaining on workers’ hands after handwashing and an increase in blood lead level. This is the first study that assessed both ventilation flow rates used in the industrial painting industry and measurements of airborne and dermal (hands) lead exposures. For the projects evaluated, the collected exposure data indicate that air velocities frequently used in the industrial painting industry to ventilate field containment structures did not tend to prevent an increase in worker blood lead and were ineffective for adequately controlling elevated concentrations of airborne lead and preventing contact with workers’ hands.

Effect of occupational lead exposure on the blood pressure of lead-exposed workers

Objective To investigate the effect of occupational lead exposure on blood pressure and provide supportive evidence of health protection on lead-exposed workers.Methods 612 workers(452 lead-exposed workers,160workers as control)were recruited in the battery factory.The blood lead concentration and blood pressure were detected by occupational health examination and

Lead acetate in drinking water is toxic to hippocampal tissue Measuring relative protein changes using tissue array detection

BACKGROUND: Lead can cause structural changes in the hippocampus, followed by damage to learning and memory functions, but its specific mechanisms are not yet clear. OBJECTIVE: To observe long-term toxicity of high-dose lead in drinking water on hippocampal tissue in rats, and analyze the potential association of oxidative damage, cell apoptosis, and pathology. DESIGN, TIME AND SETTING: A randomized, controlled animal experiment was performed at the Center for Medical Experiment, Lanzhou General Hospital of Lanzhou Military Area Command of Chinese PLA from May 2007 to October 2008. MATERIALS: Rabbit anti Bcl-2, Bax, and inducible nitric oxide synthase (iNOS) polyclonal antibodies were purchased from Santa Cruz Biotechnology, USA. An streptavidin-peroxidase immunohistochemistry kit and concentrated DAB kit were purchased from Beijing Zhongshan Biotechnology Company Limited, China. Crystal violet was purchased from Sigma, USA. METHODS: A total of 72 Wistar rats, aged 3 months, were randomly divided into control, low-, middle-, and high-dose lead groups, with 18 rats per group. Animal models were established through free drinking water contaminated by Pb2+ for 1, 3, and 6 months, respectively. MAIN OUTCOME MEASURES: The general toxicity of lead was dynamically observed; the levels of Pb2+ in the blood and brain tissue homogenate were detected using atomic absorption method; pathological changes were observed using hematoxylin-eosin staining and tigroid body staining; the protein expression levels of Bcl-2, Bax, and iNOS were dynamically observed using streptavidin-peroxidase immunohistochemistry of the hippocampus. RESULTS: Lead exposure reduced autonomic activities, produced a slumped appearance, slow responses, and lusterless fur, especially in the high-dose group. The amount of ingestion and hydroposia showed a decreasing trend, especially in middle- and high-dose groups. Lead levels in whole blood and brain homogenate were higher than controls (P < 0.01). Lead caused degeneration of hippocampal neurons and pyknosis, with fewer tigroid bodies, especially in high-dose lead group. Bcl-2 expression decreased with increasing lead dose (P < 0.01), whereas lead dose-dependently increased Bax levels (P < 0.01) and iNOS levels (P < 0.05). CONCLUSION: High levels of Pb2+ may disrupt hippocampal structure by passing through the blood brain barrier. Oxidative damage and apoptosis may be a toxicity mechanism of Pb2+ on the hippocampus.

Higher rates of autism and attention deficit/hyperactivity disorder in American children:Are food quality issues impacting epigenetic inheritance?

In the United States,schools offer special education services to children who are diagnosed with a learning or neurodevelopmental disorder and have difficulty meeting their learning goals.Pediatricians may play a key role in helping children access special education services.The number of children ages 6-21 in the United States receiving special education services increased 10.4%from 2006 to 2021.Children receiving special education services under the autism category increased 242%during the same period.The demand for special education services for children under the developmental delay and other health impaired categories increased by 184%and 83%respectively.Although student enrollment in American schools has remained stable since 2006,the percentage distribution of children receiving special education services nearly tripled for the autism category and quadrupled for the developmental delay category by 2021.Allowable heavy metal residues remain persistent in the American food supply due to food ingredient manufacturing processes.Numerous clinical trial data indicate heavy metal exposures and poor diet are the primary epigenetic factors responsible for the autism and attention deficit hyperactivity disorder epidemics.Dietary heavy metal exposures,especially inorganic mercury and lead may impact gene behavior across generations.In 2021,the United States Congress found heavy metal residues problematic in the American food supply but took no legislative action.Mandatory health warning labels on select foods may be the only way to reduce dietary heavy metal exposures and improve child learning across generations.