OBJECTIVETo determine whether lead affects brainstem auditory evoked potentials (BAEPs) in low-to-moderate lead exposed children.

METHODSBAEPs were recorded from 114 asymptomatic children aged 1 - 6 years. Average values were calculated for peak latency (PL) and amplitude (Amp). Whole blood lead (PbB) levels were assessed by graphite furnace atomic absorption spectroscopy. Based on their PbB levels, subjects were divided into low lead (PbB < 100 micro g/L) and high lead subgroups (PbB > or = 100 micro g/L).

RESULTSThe PbB levels of the 114 subjects ranged from 32.0 to 380.0 micro g/L in a positively skewed distribution. The median of PbB levels was 90.0 micro g/L while the arithmetic average was 88.0 micro g/L. Of the subjects, 43.0% (49/114) had levels equal to or greater than 100 micro g/L. Bilateral PLs I, V, and III of the left ear in the high lead subgroup were significantly longer than those in the low lead subgroup (P < 0.05). A positive correlation was found between PbB levels and bilateral PLs I, V and III of the left ear (P < 0.05), after controlling for age and gender as confounding factors. A significant and positive correlation between PbB levels and PL I of the left ear, even when PbB levels were lower than 100 micro g/L, in the low subgroup (r = 0.295, P = 0.019) was also found.

CONCLUSIONSLead poisoning in children younger than 6 years old is a very serious problem to which close attention should be paid. The indications that lead prolongs partial PLs may imply that lead, even at PbB levels lower than 100 micro g/L, impairs both the peripheral and the central portions of the auditory system. BAEPs may be a sensitive detector of subclinical lead exposure effects on the nervous system in children.

Child ; Child, Preschool ; Evoked Potentials, Auditory, Brain Stem ; drug effects ; Female ; Humans ; Infant ; Lead ; blood ; toxicity ; Lead Poisoning ; physiopathology ; Male

OBJECTIVEPrunalla vulgaris was used as the experimental material to study the effects of lead (Pb), copper (Cu) and cadmium (Cd) on the related physiological and growth indexes of the plant.

METHODBy referencing the GAP and the soil environmental quality standard, the growth and inherent quality of the plant were observed under different concentrations of the heavy metals stresses. The data were statistically processed.

RESULTThe results showed that the plant grew normally when the heavy metal concentrations in soil were close to up limits of the soil environmental quality standard II. The content of heavy metal in spica met the requirement of the standard, and under the circumstances the content of ursolic acid was increased in a certain range. The critical values of Pb, Cu, Cd in the P. vulgaris grown soil were set at 450, 100, 1.0 mg x kg(-1), respectively.

CONCLUSIONThe harmful influence of the heavy metal stress at a lower concentration is lighter than at a higher concentration, and it could increase the content of ursolic acid. The stress of Pb, Cu and Cd is more obvious than that of Zn.

Cadmium ; toxicity ; Copper ; toxicity ; Lamiaceae ; drug effects ; growth & development ; physiology ; Lead ; toxicity ; Plants, Medicinal ; drug effects ; growth & development ; physiology

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.
Adult ; Coal Mining ; Environmental Pollutants ; toxicity ; Humans ; Isoprostanes ; blood ; Lead ; blood ; toxicity ; Male ; Occupational Exposure ; Oxidative Stress ; drug effects

OBJECTIVETo explore the effects of lead on the thyroid function of occupationally exposed workers.

METHOD157 workers occupationally exposed to lead in a smelting factory were investigated. The concentration of lead in air at workshop was measured by flame atomic absorption spectrophotometry (FAAS) and the levels of blood lead (PbB) by atomic absorption spectrophotometry (AAS), zinc protoporphyrin (ZPP) by ZnPP meter, as well as the indexes of thyroid function, thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), thyroxin (T(4)), free T(3) (FT(3)), and free T(4) (FT(4)) in serum by radioimmunoassay.

RESULTSThe workers with higher level of blood lead (> 2.88 micro mol/L) showed lower levels of T(3) [(1.54 +/- 0.39) nmol/L] and FT(3) [(5.50 +/- 1.26) pmol/L] than those with lower blood lead level [PbB: (1.92 approximately 2.88) micro mol/L group, T(3): (1.71 +/- 0.45) nmol/L, FT(3): (6.12 +/- 1.64) pmol/L, P < 0.05]. There was no obvious effect of length of service on thyroid hormone of exposed workers.

CONCLUSIONHigher level of blood lead may cause certain damage to thyroid function by inhibiting deiodination of T(4). No obvious relation between length of service and thyroid function was found.

Adult ; Female ; Humans ; Lead ; blood ; toxicity ; Male ; Middle Aged ; Occupational Exposure ; Thyroid Gland ; drug effects ; physiology

OBJECTIVETo observe the effects of lead on mRNA and protein expression of PKC in U251 cell line.

METHODSAfter U251 cells were exposed to 0.05, 0.50, 5.00, 50.00, 500.00, 900.00 and 1000.00 micromol/L Ph(Ac)2 for 24 hours, the cytotoxicity of Pb on U251 cells was measured by MTT assay. RT-PCR and Western blot assay were used to detect the mRNA and protein expression levels of PKC in U251 cells exposed to 0.05, 5.00 and 500.00 micromol/L Ph (Ac), for 24 hours.

RESULTSThe survival rates of U251 cells treated with 5.00, 50.00, 500.00, 900.00 and 1000.00 micromol/L Pb (Ac)2 were 84.5%, 78.2%, 76.5%, 50.3% and 43.2%, respectively, which were significantly lower than those of control group (P < 0.01). The PKC mRNA expression level (0.40 +/- 0.01) of U251 cells treated with 500.00 micromol/L Pb (Ac)2 was significantly lower than that (0.51 +/- 0.02) of control group (P < 0.01). The PKC protein expression levels of U251 cells treated with 0.05, 5.00 or 500.00 micromol/L Pb(Ac)2 were 0.68 +/- 0.02, 0.62 +/- 0.01 and 0.33 +/- 0.02, respectively, which were significantly lower (0.98 +/- 0.01) than those of control group (P < 0.01).

CONCLUSIONLead can decline the cell viability, PKC mRNA and protein expression levels of U251 cells.

Cell Line, Tumor ; Cell Survival ; Humans ; Lead ; toxicity ; Protein Kinase C ; metabolism ; RNA, Messenger ; metabolism

Humans ; Lead ; toxicity ; Male ; Reproduction ; drug effects ; Sperm Count ; Sperm Motility ; drug effects

Adult ; Female ; Humans ; Lead ; toxicity ; MMPI ; Male ; Middle Aged ; Occupational Exposure ; Personality ; drug effects

Child ; Child, Preschool ; China ; epidemiology ; Data Collection ; Health Policy ; Humans ; Infant ; Infant, Newborn ; Lead ; blood ; toxicity ; Lead Poisoning ; blood ; complications ; epidemiology ; prevention & control ; Risk Factors

Heavy metal is one of pollutants existed widely in the environment, its relationship with cardiovascular disease has attracted more and more attention. In this review, the concentrations of heavy metals, including lead, cadium and asenic, in the body from several national surveillance networks and the epidemiological studies on the effects of the exposure of three heavy metals on cardiovascular system were summarized. It is suggested to strengthen nationwide surveillance for body concentrations of heavy metals in general population in order to provide baseline data for quantitative evaluation of the risk of heavy metal exposure on cardiovascular disease.
Cadmium ; Cardiovascular Diseases/chemically induced* ; Environmental Exposure/adverse effects* ; Environmental Pollutants/toxicity* ; Epidemiologic Studies ; Humans ; Lead/toxicity* ; Metals, Heavy/toxicity* ; Neoplasms ; Research/trends*

BACKGROUNDLead exposure during pregnancy contributes to fetal abortion and/or teratogenesis. Endoplasmic reticulum (ER) apoptosis can be induced by various pathological conditions when ER function is disturbed. However, it is unclear whether ER stress and apoptosis play a role in the etiology of lead-exposed disease status. We aimed to investigate whether lead induced placental apoptosis and subsequent toxicity is initiated by ER apoptosis via caspase-12.

METHODSSixty-three female Wistar rats were exposed to lead in drinking water during various gestational periods. Blood lead level was determined by atomic absorption spectrophotometry. Placental cytoplasmic organelles were examined by electronic microscopy. Placental caspase-12 mRNA expression was evaluated by qRT-PCR. TUNEL assay was used to determine the placental apoptosis.

RESULTSLead exposure significant induced ER apoptosis compared to that of the controls (P < 0.05), accompanied with increased caspase-12 mRNA expression. Significant differences of caspase-12 mRNA expression levels were observed among the four groups (F = 13.78, P < 0.05). Apoptotic index (AI) was significantly increased in experimental groups compared to that of the controls (F = 96.15, P < 0.05). In lead-exposed groups, trophoblast cells underwent degeneration and fibrin deposition; Mitochondria were swollen and decreased in number; ER swelling, expansion, and vacuolization were observed.

CONCLUSIONLead exposure contributes to placental apoptosis, as well as increased caspase-12 mRNA expression, which in turn promoted ER stress.

Animals ; Apoptosis ; drug effects ; Endoplasmic Reticulum Stress ; drug effects ; Female ; Lead ; toxicity ; Placenta ; cytology ; ultrastructure ; Pregnancy ; Rats ; Rats, Wistar