Effects of occupational lead exposure on lumbar vertebral fracture in male workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of occupational lead exposure on lumbar vertebral fracture in exposed male workers.</p><p><b>METHODS</b>One hundred and fifty-two lead-exposed male workers in a storage battery plant in Shanghai were selected as the study population. The blood lead (BPb) and the urinary lead (UPb) were measured by graphite-furnace atomic absorption spectrometry (GF-AAS). Bone mineral density (BMD) was measured by the monophoton absorptiometry(SPA-4) and Z score was determined. Anteroposterior and lateral lumbar spinal X-ray films were taken to determine lumbar vertebral fracture.</p><p><b>RESULTS</b>For the occupationally lead-exposed workers, geometric mean of BPb was 0.85 (0.33 approximately 1.90) micromol/L, geometric mean of UPb was 4.84 (0.46 approximately 21.31) microg/g Cr, and the prevalence of lumbar vertebral fracture was 19.7%. The prevalence of lumbar vertebral fracture would increase with the increase of age and work year, but with no significantly statistical difference (P > 0.05). The bone mineral density (BMD) would decrease with the increase of BPb and UPb (P < 0.05). The prevalence of lumbar vertebral fracture would increase significantly with the increase of the lead exposure (P < 0.05) with the linear correlation (P < 0.05). The prevalence of lumbar vertebral fracture would increase significantly with the decrease of the bone mass (P < 0.01) with the linear correlation (P < 0.01).</p><p><b>CONCLUSION</b>The occupational exposure to lead could cause the decrease of the bone mineral density and the increase of the prevalence of lumbar vertebral fracture. The development of lumbar vertebral fracture is associated with the decrease of bone mass.</p>

Effects of occupational lead exposure on bone mineral density and bone metabolism in workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of occupational lead exposure on the bone mineral density and the bone metabolism in exposed workers.</p><p><b>METHODS</b>Two hundred and ninety-eight lead-exposed workers in a storage battery plant in Shanghai were selected as the exposed subjects while eighty-one healthy officers in the plant who were not occupationally exposed to lead were treated as the control. The blood lead (BPb) and the urinary lead (UPb) were used as the exposure biomarkers while the Z score, the urinary hydroxyproline (HYP) the serum alkaline phosphatase (ALP) the serum alkaline phosphatase bone isoenzyme BALP and the serum osteocalcin BGP were used as the effect biomarkers for the bone effect caused by the lead. Bone mineral density (BMD) was measured by the single-photon absorptiometry (SPA-4).</p><p><b>RESULTS</b>The BPb, UPb, HYP, ALP, BALP in the occupational lead exposure group were higher than those in the control group with significantly statistical difference in male (P < 0.01). The levels of BGP in the exposure group was higher than that in the control group without significantly statistical difference (P > 0.05). The BMD in the exposure group was lower than that in the control group without significantly statistical difference (P > 0.05). The BMD was significantly decreased in the groups of the UPb 10 approximately microg/g Cr level compared with the 0 approximately microg/g Cr group with the significant difference (P < 0.01). In males, the BMD was significantly decreased in the group of the BPb 300 approximately microg/L level compared with the 0 approximately microg/L group with the significant difference (P < 0.01). The levels of HYP, ALP, BALP, BGP in the UPb 20 approximately microg/g Cr group were significantly higher than those in the UPb 0 approximately microg/g Cr group (P < 0.05). The levels of HYP, ALP, BALP, BGP in the BPb 300 approximately microg/L group were significantly higher than those in the BPb 0 approximately microg/L group (P < 0.05). The prevalence of both osteoporosis and the abnormal bone metabolisms indexes would increase significantly with the increase of the lead exposure (P < 0.01) with the linear correlation (P < 0.01). But the prevalence of higher BGP had no significant correlation with UPb (P > 0.05). BMDs were calculated using BMDS Version 1.3.2 software and BMDLs were also determined. The BMDLs of BPb and UPb for lead-induced osteoporosis were higher than those representing the change of bone metabolism induced by lead.</p><p><b>CONCLUSIONS</b>The occupational exposure to lead could cause the decrease of the bone mineral density, lead to the osteoporosis, and may affect the bone metabolism.</p>

Effects of CO2 on high density culture of Chaetoceros mulleri / 生物工程学报

The effect of CO2 and the manner of CO2 offer on the growth rate and maximual cell density of ultro-high density culture of Chaetoceros mulleri in the photobioreactor were studied in the work. The amount of CO2 offered to the culture was controlled by the parameter of pH value in the culture. Furthermore the growth kinetics of Chaetoceros muller in the photobioreactor was studied. The results showed requirement of CO2 by the cells and the increase of pH in the culture were the key limiting factors to the growth, when a high cell concentration in the culture was reached. The offer of CO2 could improve the statute of CO2, could control the pH in the culture and increase the growth rate and maximum cell density. The results from the experiments of CO2 offer manner showed different efficiency to growth was resulted from differences of CO2 offer manner. The best way is mixing the CO2 and air before the CO2 was offered to the culture.