Study on the effects of lead from small industry of battery recycling on environment and children's health / 中华流行病学杂志

<p><b>OBJECTIVE</b>In order to minimize lead pollution and to protect the identified individuals with high blood lead level from lead contamination, an epidemiological study was carried on children living around the village and township-owned lead industries in Tianying town.</p><p><b>METHODS</b>Environmental monitoring: lead levels in air, soil, drinking water and crops were measured. Biological monitoring: 959 children aged 5 - 12 years were selected from villages where the lead smelters located near the residential areas and the battery disassembling was done in some families. The control children (207 pupils) were from other villages without lead exposure. Blood lead, ZnPP and teeth lead were determined. Height, weight and head circle of children and IQ scores were measured.</p><p><b>RESULTS</b>The environment was seriously polluted. The average lead concentrations in air and soils were 8.5 times and 10 times of the MACs (national health standard) respectively. Eighty-five per cent the air samples with lead concentrations higher than the national health standard. Local crops and wheat at farmers' home were also contaminated by lead dust, with. Lead content being 24 times higher than the standard. The mean blood lead and ZnPP levels of children lived in the polluted areas were 496 microgram/L and 9.41 microgram/g Hb respectively. The lead exposure caused adverse effects on children's IQ and physical development.</p><p><b>CONCLUSION</b>It is necessary to remove and reduce currently active sources of lead pollution in the community and to increase public awareness of potential health effects of lead exposure.</p>

Stimulation single fiber electromyography in rats with myasthenia induced by organophosphorus insecticides and their mixtures poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the neuromuscular function and its relation with the occurrence of myasthenia in rats poisoned by dimethoate (D), phoxim (P), methomyl (M), M + D and M + P respectively.</p><p><b>METHODS</b>The stimulation single fiber electromyography(SSFEMG) at different stimulus frequencies(5, 10 and 20 Hz) was used. The whole blood cholinesterase (ChE) activity was measured 1 h before and after poisoning.</p><p><b>RESULTS</b>(1) Myasthenia occurred in 5 out of 9.5 out of 10.5 out of 5, and 8 rats poisoned by D, P, M + D, and M + P, respectively. (2) The average mean consecutive differences(MCD) at 5, 10, and 20 Hz in myasthenic rats were significantly higher than those of poisoned rats without myasthenia and the control ones. (3) SSFEMG changes at 5, 10 and 20 Hz were significantly consistent with the clinical manifestation of myasthenia, especially at 10 Hz and 20 Hz. (4) ChE activity was significantly lower in rats with P or D poisoning while ChE inhibition was of no difference in rats with M, M + D, and M + P poisoning. In the D poisoning and P poisoning groups, there was no significant difference in ChE inhibition between the rats with and without myasthenia.</p><p><b>CONCLUSION</b>Muscle weakness was associated with neuromuscular transmission dysfunction, but not well correlated with ChE inhibition. The SSFEMG with stimulus frequency at 10 Hz or 20 Hz could be used to detect the neuromuscular dysfunction during myasthenia induced by organophosphate insecticides and their mixtures poisoning.</p>