Evaluation the Effect of Serum Lead Levels on Thyroid Function in Battery Industry Workers.

Objective: To assess the relationships between blood lead levels and thyroid functional tests in battery industry workers. Methods and Materials: This cross-sectional study was performed on 100 personnel of a battery factory in 2019. The checklist including demographic information of employees (age, sex, work experience, smoking, etc.) of the work shift, work environment, and duration of work was completed. Venous blood samples were also taken from the participants to check blood levels of lead and thyroid hormones. Results: The mean age of participants was 36.1 ± 5.6 years and their mean TSH and lead levels were 3.69 ± 2.45 mIU/L and 297.9 ± 174.2 µg/L, respectively. Participants were divided into two groups based on job duties: administrative and working in the production line. Participants were divided into two groups based on blood lead levels: normal (less than 300 µg/L) and high lead level (more than 300 µg/L). Only the work experience between these two groups was significantly different and was higher in the high lead group compared to the normal lead group and no significant difference was observed between different groups based on lead level in terms of TSH level and thyroid hormones. Conclusion: Our study showed that although the amount of whole blood lead concentration is not related to thyroid hormone levels and thyroid function, but with increasing work experience, the amount of whole blood lead also increases significantly and since lead poisoning can have many health hazards, employers must plan to minimize the lead exposure of workers and provide protective equipment for workers.

Evaluation of the Hybrid Membrane of ZnO Particles Supported in Cellulose Acetate for the Removal of Lead.

Water polluted by discarded heavy metals such as lead is creating a global pollution problem. In this work, adsorption of Pb(II) was realized in batch studies by a hybrid membrane of cellulose acetate with ZnO particles. First, ZnO particles were prepared by precipitation and immobilized on the membrane. The hybrid membrane was elaborated by interfacial polymerization. The structure and surface were characterized based on Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Batch experiments were carried out under different conditions where the number of particles of ZnO present in the membrane and the pH of the aqueous solution were varied. The Langmuir and Freundlich isotherm models were evaluated in the best adsorption conditions. Data fitted well with a Langmuir model with a maximum adsorption capacity of 15.55 mg·g-1, which was similar for this type of materials. Thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy showed that the process was spontaneous and favorable. The hybrid membrane was evaluated in simulated wastewater of the battery industry with a superior efficiency of up to 97%; without the medium, it did not generate interference. These results suggest that Pb(II) removal by hybrid membrane is possible.

In situ polymerization of magnetic graphene oxide-diaminopyridine composite for the effective adsorption of Pb(II) and application in battery industry wastewater treatment.

The efficient removal of heavy metals from aqueous environment is imperative and challenging. A novel ternary composite constructed of diaminopyridine polymers, graphene oxide, and ferrite magnetic nanoparticles was designed by a facile in situ polymerization strategy for the removal of Pb(II) from aqueous solution. Detailed characterization of morphological, chemical, and magnetic properties was employed systematically to confirm the formation of the composite material. Batch adsorption experiment studies suggested that the composite was an excellent adsorbent for Pb(II) which was easily collected after use via exposure to an external magnetic field for 30 s. The effects of different parameters such as solution pH, adsorbent dosage, contact time, initial Pb(II) concentration, temperature, and co-existing ions were examined. The maximum adsorption capacity at pH = 5 was estimated to be 387.2 mg g-1 at 298 K by the Langmuir isotherm model, accompanied by favorable adsorption recyclability according to the investigation of regeneration experiments. Thermodynamic studies revealed that the Pb(II) adsorption via our ternary composite was endothermic and spontaneous. The corresponding removal performance for effluent containing Pb(II) from the battery industry was successfully examined. The present results indicated that our designed adsorbent is beneficial to the practical Pb(II) removal in wastewater purification.

Rapid adsorptive removal of toxic Pb(2+) ion from aqueous solution using recyclable, biodegradable nanocomposite derived from templated partially hydrolyzed xanthan gum and nanosilica.

This work studied the application of a novel biodegradable nanocomposite based on partially hydrolyzed polyacrylamide grafted xanthan gum and nanosilica (h-XG/SiO2) towards efficient and rapid removal of toxic Pb(2+) ions from aqueous environment. The uptake ability of Pb(2+) using h-XG/SiO2 has been studied in batch adsorption experiments with variation of adsorption parameters. The excellent removal rate (99.54% adsorption within 25min) and superior adsorption capacity (Qmax=1012.15mgg(-1)) of the composite material have been explained on the basis of synergistic and chelating effects of h-XG/SiO2 with Pb(2+) ion through electrostatic interactions. The kinetics, isotherm and thermodynamics studies reveal that Pb(2+) adsorb rapidly on nanocomposite surface, which is in agreement with pseudo-second-order kinetics and Langmuir adsorption isotherm models. In consequence of excellent adsorption as well as regeneration characteristics of nanocomposite, it has been found to be a promising adsorbent towards removal of Pb(2+) ions from battery industry wastewater.

Occupational exposure to lead decreases macular, choroidal, and retinal nerve fiber layer thickness in industrial battery workers.

PURPOSE: To evaluate the toxic effects of chronic lead (Pb) exposure on retinal nerve fiber layer thickness (RNFLT), macular thickness (MT) and choroidal thickness (CT) in battery industry workers. MATERIALS AND METHODS: Male factory workers (n = 50) and healthy non-employees (n = 20) participated in the study. Group 1 (n = 22) comprised lead workers; Group 2 (n = 16), box makers; Group 3 (n = 12), assistant personnel; and Group 4 (n = 20), healthy non-employees. All participants were given Best-Corrected Visual Acuity (BCVA) tests, full ophthalmologic examinations, and Spectral Domain Optical Coherence Tomography (SD-OCT) of the optic nerve head, RNFL, macula, and choroid. Blood lead levels (BLL) in venous blood samples were determined. The duration of exposure to lead varied, and is expressed in months. RESULTS: Average (mean ± SD) ages of participants were 27.55 ± 4.00, 28.69 ± 3.48, 32.00 ± 3.38, and 29.85 ± 5.48 yrs (Groups 1-4, respectively). BLL were 46.2 ± 2.32, 29.31 ± 3.30, 16.9 ± 1.9, and 2.85 ± 0.98 µg/dL (Groups 1-4, respectively). Durations of exposure to lead were 43.86 ± 10.81, 42.81 ± 4.86, and 49.42 ± 6.14 mo (Groups 1-3, respectively). OCT averages for RNFL were 101.68 ± 5.32, 119.50 ± 13.47, 127.67 ± 8.92, and 130.9 ± 6.63 µm (Groups 1-4, respectively). Although RNFLTs of Group 1 were significantly less than those of for Groups 2-4, and, RNFLTs of Groups 2 and 3 were significantly less than that of Group 4, there were no significant differences between Group 2 and 3. MTs were 94.50 ± 6.78, 105.63 ± 5.43, 111.50 ± 6.74 and 147.95 ± 6.67 µm, (Groups 1-4, respectively). CTs were 176.41 ± 15.39, 222.19 ± 17.79, 239.17 ± 15.64, and 251.50 ± 10.98 µm (Groups 1-4, respectively). Both MTs and CTs displayed significant differences among the four groups. CONCLUSIONS: Ocular changes in individuals who are chronically exposed to lead include decrease in RNFT, MT, and CT, and thus these parameters should be evaluated during ophthalmologic examination of individuals working in lead-based industries.