饲料钙水平对淡水养殖鲈血清渗透压和离子调节的影响

为了研究饲料钙水平对淡水养殖鲈Lateolabrax japonicus血清渗透压、离子水平以及与渗透压调节有关酶活力的影响,以体质量为(12.47±0.01)g的鲈为研究对象,分别投喂钙水平为0.29%(D1)、0.42%(D2)、0.65%(D3)、0.79%(D4)、1.02%(D5)、3.10%(D6)的6种等氮等能饲料,共饲养8周。结果表明:随着饲料中钙水平的提高,D1、D2组血清渗透压无显著性差异(P>0.05),均显著高于D3、D4和D5组(P<0.05),与D6组无显著性差异(P>0.05);血清Na+水平和Cl-水平的变化趋势相似,均随着饲料钙水平的提高呈先上升后降低的趋势(P<0.05),其中D1、D2和D6组血清Na+和Cl-水平均低于其他各组,血清Ca2+水平D5组最高,D6组最低,其他各组均无显著性差异(P>0.05);随着饲料中钙水平的提高,鳃丝Na+/K+-ATP(NKA)酶活力呈先降低后升高趋势,D1组酶活力最高(P<0.05),而Ca2+-ATP(CA)酶活力总体呈降低趋势,也以D1组酶活力最高(P<0.05),肠道中NKA酶活力呈先上升后降低趋势,D3组酶活力最高(P<0.05),肠道中CA酶活力D1和D3组较高,D6组最低,肾脏中NKA酶活力和CA酶活力均随着饲料中钙水平的提高呈先降低后升高的趋势,NKA酶活力D1组最高,D4组最低,而CA酶活力D1、D3组较高,D4组最低。研究表明,低钙饲料(0.29%和0.42%钙水平)和高钙饲料(3.10%钙水平)均会使淡水养殖鲈处于高强度的渗透压调节状态,而含钙0.65%¹.02%的饲料有利于其渗透压平衡调节。     

盐度对梭鱼幼鱼生长、渗透生理和体成分组成的影响

为研究盐度对梭鱼Liza haematocheila幼鱼生长、渗透生理和体成分组成的影响,在水温16²1℃下,将体质量为(1.28±0.25)g的梭鱼幼鱼在盐度为0.8、5.0、10.0(对照)、15.0、20.0、25.0、30.0、35.0的室内循环养殖系统(100 L)中饲养6周。结果表明:各盐度下梭鱼幼鱼的特定生长率和相对增重率无显著性差异(P>0.05);盐度为0.8的组成活率最低,且显著低于除盐度为5.0组之外的其余各组(P<0.05),盐度为10.0及以上的各组间无显著性差异(P>0.05);盐度为0.8的组饲料系数最大(P<0.05),且显著高于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为5.0、10.0的组摄食率最低,且显著低于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为35.0的组血清渗透压最高(P<0.05),盐度为0.8的组血清渗透压最低(P<0.05);通过回归分析得到血清渗透压等渗点为0.319 mol/kg,所对应的盐度为11.3;血清Na+、K+、Cl-离子含量随盐度的升高整体呈上升趋势;盐度为25.0的组鳃丝Na+/K+-ATP酶活力最低,仅显著低于盐度为0.8、15.0的组(P<0.05),盐度为0.8和15.0的组酶活力最高;梭鱼幼鱼体水分含量随盐度的升高呈下降趋势,粗蛋白质、粗脂肪和粗灰分含量随盐度的升高呈上升趋势。研究表明,梭鱼幼鱼的等渗点相当于盐度11.3,且具有较强的盐度耐受能力,可以适应0.821℃下,将体质量为(1.28±0.25)g的梭鱼幼鱼在盐度为0.8、5.0、10.0(对照)、15.0、20.0、25.0、30.0、35.0的室内循环养殖系统(100 L)中饲养6周。结果表明:各盐度下梭鱼幼鱼的特定生长率和相对增重率无显著性差异(P>0.05);盐度为0.8的组成活率最低,且显著低于除盐度为5.0组之外的其余各组(P<0.05),盐度为10.0及以上的各组间无显著性差异(P>0.05);盐度为0.8的组饲料系数最大(P<0.05),且显著高于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为5.0、10.0的组摄食率最低,且显著低于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为35.0的组血清渗透压最高(P<0.05),盐度为0.8的组血清渗透压最低(P<0.05);通过回归分析得到血清渗透压等渗点为0.319 mol/kg,所对应的盐度为11.3;血清Na+、K+、Cl-离子含量随盐度的升高整体呈上升趋势;盐度为25.0的组鳃丝Na+/K+-ATP酶活力最低,仅显著低于盐度为0.8、15.0的组(P<0.05),盐度为0.8和15.0的组酶活力最高;梭鱼幼鱼体水分含量随盐度的升高呈下降趋势,粗蛋白质、粗脂肪和粗灰分含量随盐度的升高呈上升趋势。研究表明,梭鱼幼鱼的等渗点相当于盐度11.3,且具有较强的盐度耐受能力,可以适应0.8³5.0盐度的水体。     

盐度对梭鱼幼鱼生长、渗透生理和体成分组成的影响

为研究盐度对梭鱼Liza haematocheila幼鱼生长、渗透生理和体成分组成的影响,在水温16~21℃下,将体质量为(1.28±0.25)g的梭鱼幼鱼在盐度为0.8、5.0、10.0(对照)、15.0、20.0、25.0、30.0、35.0的室内循环养殖系统(100 L)中饲养6周。结果表明:各盐度下梭鱼幼鱼的特定生长率和相对增重率无显著性差异(P>0.05);盐度为0.8的组成活率最低,且显著低于除盐度为5.0组之外的其余各组(P<0.05),盐度为10.0及以上的各组间无显著性差异(P>0.05);盐度为0.8的组饲料系数最大(P<0.05),且显著高于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为5.0、10.0的组摄食率最低,且显著低于其余各组(P<0.05),其余各组间无显著性差异(P>0.05);盐度为35.0的组血清渗透压最高(P<0.05),盐度为0.8的组血清渗透压最低(P<0.05);通过回归分析得到血清渗透压等渗点为0.319 mol/kg,所对应的盐度为11.3;血清Na+、K+、Cl-离子含量随盐度的升高整体呈上升趋势;盐度为25.0的组鳃丝Na+/K+-ATP酶活力最低,仅显著低于盐度为0.8、15.0的组(P<0.05),盐度为0.8和15.0的组酶活力最高;梭鱼幼鱼体水分含量随盐度的升高呈下降趋势,粗蛋白质、粗脂肪和粗灰分含量随盐度的升高呈上升趋势。研究表明,梭鱼幼鱼的等渗点相当于盐度11.3,且具有较强的盐度耐受能力,可以适应0.8~35.0盐度的水体。     

饲料浮萍水平对黄金锦鲤生长性能、消化酶活力及抗氧化能力的影响

为研究浮萍Lemna minor对黄金锦鲤Cyprinus carpio生长性能、抗氧化和消化能力的影响,以初始体质量为(52.99±1.95)g的黄金锦鲤为研究对象,在饲料中分别添加0、3%、6%、9%、13%、14%的浮萍,相应替代同等水平的菜粕,制成6组等氮(粗蛋白质为38.5%³8.6%)、等能(12.2 MJ/kg)的饲料,分别记为D1(对照)、D2、D3、D4、D5、D6饲料组,将540尾健康的黄金锦鲤随机分成6组,每组设3个重复,每个重复放30尾鱼,养殖时间为8周。结果表明:D6饲料组增重率(WGR)、蛋白质效率(PER)、特定生长率(SGR)和肥满度(CF)均显著高于对照组及添加水平为3%的饲料组(P<0.05),而其饲料系数(FCR)显著低于上述两组(P<0.05);D6饲料组蛋白酶活力与脂肪酶活力显著高于其他饲料组(P<0.05),各饲料组间淀粉酶活力则无显著性差异(P>0.05);D4与D6饲料组肝胰脏、脾脏、肾脏和血清中的超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活力显著高于其他饲料组(P<0.05),且D6饲料组丙二醛(MDA)活力显著最低(P<0.05)。研究表明:本试验条件下,饲料中浮萍的添加水平在14%时,有利于黄金锦鲤的生长,并能提高鱼体抗氧化能力与消化酶活力。     

饲料浮萍水平对黄金锦鲤生长性能、消化酶活力及抗氧化能力的影响

为研究浮萍Lemna minor对黄金锦鲤Cyprinus carpio生长性能、抗氧化和消化能力的影响,以初始体质量为(52.99±1.95)g的黄金锦鲤为研究对象,在饲料中分别添加0、3%、6%、9%、13%、14%的浮萍,相应替代同等水平的菜粕,制成6组等氮(粗蛋白质为38.5%~38.6%)、等能(12.2 MJ/kg)的饲料,分别记为D1(对照)、D2、D3、D4、D5、D6饲料组,将540尾健康的黄金锦鲤随机分成6组,每组设3个重复,每个重复放30尾鱼,养殖时间为8周。结果表明:D6饲料组增重率(WGR)、蛋白质效率(PER)、特定生长率(SGR)和肥满度(CF)均显著高于对照组及添加水平为3%的饲料组(P<0.05),而其饲料系数(FCR)显著低于上述两组(P<0.05);D6饲料组蛋白酶活力与脂肪酶活力显著高于其他饲料组(P<0.05),各饲料组间淀粉酶活力则无显著性差异(P>0.05);D4与D6饲料组肝胰脏、脾脏、肾脏和血清中的超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活力显著高于其他饲料组(P<0.05),且D6饲料组丙二醛(MDA)活力显著最低(P<0.05)。研究表明:本试验条件下,饲料中浮萍的添加水平在14%时,有利于黄金锦鲤的生长,并能提高鱼体抗氧化能力与消化酶活力。     

饲料脂肪水平对淡黑镊丽鱼生长及色素蓄积的影响

为研究饲料脂肪水平对淡黑镊丽鱼Labidochromis caeruleus生长、体态及色素积累的影响,选取淡黑镊丽幼鱼120尾(初始体质量为1.70 g±0.09 g),分为Z1(对照)、Z2、Z3、Z4、Z5共5组,投喂饲料脂肪水平分别为7.44%、9.86%、10.91%、15.25%和23.69%的等氮饲料,饲料中添加叶黄素为200 mg/kg,每个试验组设3个平行,养殖68 d后测定淡黑镊丽鱼生长及色素蓄积情况。结果表明:Z3组淡黑镊丽鱼终末体质量、特定生长率和增重率均最高且显著高于Z1组(P<0.05);Z3组饲料系数最小;Z3、Z4组存活率最高,Z5组存活率最低且显著低于其他组(P<0.05);随饲料脂肪水平的增加鱼体脏体比虽有升高趋势但变化不显著(P>0.05),而Z3、Z4组肝体比则显著低于其他组(P<0.05);Z3组肥满度显著高于其他组(P<0.05);随饲料脂肪水平的升高,鱼体各组织总类胡萝卜素含量呈升高趋势;随饲料脂肪水平的增加各组鱼体亮度(L^*)无显著性变化(P>0.05),但黄度(b*)无显著性变化(P>0.05),但黄度(b^*)呈先升高后下降、红度(a*)呈先升高后下降、红度(a^*)呈升高的趋势,随着时间的延长,各组红度和黄度都持续升高;随饲料脂肪水平的增加鱼体肝脏谷丙转氨酶活力呈增加趋势,Z5组酶活力最高且显著高于Z1组(P<0.05)。研究表明,淡黑镊丽鱼饲料中适宜的脂肪水平为10.76%,饲料中脂肪过高或过低对淡黑镊丽鱼的生长和体色均有一定影响。     

饲料脂肪水平对中间球海胆幼胆生长、消化酶和热胁迫后抗氧化酶活力的影响

为了确定中间球海胆Strongylocentrotus intermedius幼胆饲料中适宜的脂肪水平,采用摄食生长试验探讨了饲料中脂肪水平(3%、6%、9%、12%和15%)对海胆幼胆存活、生长、消化酶和热胁迫后抗氧化酶活力的影响,试验共进行96 d。结果表明:试验结束时,6%饲料脂肪水平组海胆增重率最高,显著高于15%脂肪组(P<0.05);随着饲料脂肪水平的升高,中间球海胆消化道中脂肪酶活力显著升高(P<0.05),淀粉酶活力显著下降(P<0.05),胃蛋白酶活力有下降趋势(P>0.05);饲料脂肪水平显著影响热胁迫后海胆体腔液中抗氧化酶活力,其中热胁迫2 h后,12%脂肪组超氧化物歧化酶(SOD)活力最高,显著高于15%脂肪组(P<0.05);热胁迫6 h后,海胆体腔液过氧化氢酶(CAT)活力最高值出现在6%脂肪组,且高于12%和15%脂肪组。研究表明,6%饲料脂肪水平时中间球海胆幼胆的生长速率最快,6%¹2%饲料脂肪水平能够显著提高热胁迫后海胆的抗氧化能力。     

饲料中牛磺酸水平对红鳍东方鲀免疫及消化酶的影响

为研究饲料中牛磺酸水平对红鳍东方鲀Takifugu rubripes免疫功能及消化酶的影响,选用初始体质量为(32.28±0.20)g的红鳍东方鲀幼鱼,随机分为5个处理组,每组设3个重复,配制牛磺酸添加量分别为0%(T1,对照)、0.5%(T2)、1.0%(T3)、2.0%(T4)和5.0%(T5)的试验饲料,分别投喂不同的处理组,试验在15个200 L方形聚乙烯水槽中进行,养殖试验共进行56 d。结果表明:添加了不同水平牛磺酸的饲料可显著提高红鳍东方鲀肝脏中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)的活性(P<0.05),显著降低丙二醛(MDA)的含量(P<0.05),提高机体内自由基的清除能力,且在2.0%添加量时T-AOC达到峰值,而MDA含量下降到最低(P<0.05),SOD、CAT和GSH-PX在添加量为1.0%时酶活力达到峰值(P<0.05);肝脏AKP活力随饲料中牛磺酸含量的增加呈先升高后下降的趋势,在1.0%添加量时达到最大值(P<0.05),但牛磺酸对肝脏ACP活力无显著性影响(P>0.05);不同牛磺酸水平的饲料能显著提高红鳍东方鲀肠道脂肪酶活力,2.0%添加量时脂肪酶活力最高,且显著高于其他处理组(P<0.05),但牛磺酸添加量对肠道蛋白酶无显著性影响(P>0.05);1.0%、2.0%、5.0%添加量时红鳍东方鲀体表黏液溶菌酶活力显著高于对照组(P<0.05),在2.0%添加量时体表黏液溶菌酶活力达到最大值;通过对T-AOC、肠道消化酶和体表黏液溶菌酶这3个指标折线模型分析得出,红鳍东方鲀幼鱼饲料牛磺酸最适添加量为1.35～2.21 g/100 g(干饲料)。研究表明,饲料中添加牛磺酸可显著提高红鳍东方鲀的机体抗氧化及免疫能力,但过多的牛磺酸会导致抗氧化及免疫能力降低。     

饲料中牛磺酸水平对红鳍东方鲀免疫及消化酶的影响

为研究饲料中牛磺酸水平对红鳍东方鲀Takifugu rubripes免疫功能及消化酶的影响,选用初始体质量为(32.28±0.20)g的红鳍东方鲀幼鱼,随机分为5个处理组,每组设3个重复,配制牛磺酸添加量分别为0%(T1,对照)、0.5%(T2)、1.0%(T3)、2.0%(T4)和5.0%(T5)的试验饲料,分别投喂不同的处理组,试验在15个200 L方形聚乙烯水槽中进行,养殖试验共进行56 d。结果表明:添加了不同水平牛磺酸的饲料可显著提高红鳍东方鲀肝脏中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)的活性(P<0.05),显著降低丙二醛(MDA)的含量(P<0.05),提高机体内自由基的清除能力,且在2.0%添加量时T-AOC达到峰值,而MDA含量下降到最低(P<0.05),SOD、CAT和GSH-PX在添加量为1.0%时酶活力达到峰值(P<0.05);肝脏AKP活力随饲料中牛磺酸含量的增加呈先升高后下降的趋势,在1.0%添加量时达到最大值(P<0.05),但牛磺酸对肝脏ACP活力无显著性影响(P>0.05);不同牛磺酸水平的饲料能显著提高红鳍东方鲀肠道脂肪酶活力,2.0%添加量时脂肪酶活力最高,且显著高于其他处理组(P<0.05),但牛磺酸添加量对肠道蛋白酶无显著性影响(P>0.05);1.0%、2.0%、5.0%添加量时红鳍东方鲀体表黏液溶菌酶活力显著高于对照组(P<0.05),在2.0%添加量时体表黏液溶菌酶活力达到最大值;通过对T-AOC、肠道消化酶和体表黏液溶菌酶这3个指标折线模型分析得出,红鳍东方鲀幼鱼饲料牛磺酸最适添加量为1.35～2.21 g/100 g(干饲料)。研究表明,饲料中添加牛磺酸可显著提高红鳍东方鲀的机体抗氧化及免疫能力,但过多的牛磺酸会导致抗氧化及免疫能力降低。     

盐度突变对黄条鰤幼鱼渗透调节功能的影响

为探讨盐度突变对黄条鰤Seriola aureovittata幼鱼渗透调节功能的影响,试验设计了35、29(对照)、15、10、5、0共6个盐度组,分别将体质量为80～120 g的黄条鰤幼鱼放入不同盐度下进行120 h的盐度突变试验,分别在试验的6、12、24、48、72、96、120 h对黄条鰤幼鱼鳃丝中Na⁺/K+/K⁺-ATP酶活力,尿、血浆、血清中Na+-ATP酶活力,尿、血浆、血清中Na⁺、K+、K⁺、Cl+、Cl^-含量,以及尿和血浆渗透压的变化进行测定分析,并观察了盐度急性处理对黄条鰤幼鱼存活和渗透相关组织结构的影响。结果表明:盐度0条件下,黄条鰤在25 min时出现部分死亡, 50 min时全部死亡,其他各盐度组未出现死亡;盐度5、10、15试验组随着处理时间的延长,黄条鰤鳃丝Na-含量,以及尿和血浆渗透压的变化进行测定分析,并观察了盐度急性处理对黄条鰤幼鱼存活和渗透相关组织结构的影响。结果表明:盐度0条件下,黄条鰤在25 min时出现部分死亡, 50 min时全部死亡,其他各盐度组未出现死亡;盐度5、10、15试验组随着处理时间的延长,黄条鰤鳃丝Na⁺/K+/K⁺-ATP酶活力逐渐降低,总体上与对照组有显著性差异(P<0.05),盐度35组随着处理时间的延长,鳃丝Na+-ATP酶活力逐渐降低,总体上与对照组有显著性差异(P<0.05),盐度35组随着处理时间的延长,鳃丝Na⁺/K+/K⁺-ATP酶活力呈先上升后降低的趋势, 96 h后保持稳定且与48 h时无显著性差异(P>0.05),各盐度组鳃丝Na+-ATP酶活力呈先上升后降低的趋势, 96 h后保持稳定且与48 h时无显著性差异(P>0.05),各盐度组鳃丝Na⁺/K+/K⁺-ATP酶活力在72 h或96 h后根据盐度的不同呈现"U"形分布;从尿、血浆、血清中Na+-ATP酶活力在72 h或96 h后根据盐度的不同呈现"U"形分布;从尿、血浆、血清中Na⁺、K+、K⁺、Cl+、Cl^-浓度变化看,盐度5、10、15组,在6～72 h内各离子浓度持续降低,整体上与对照组有显著性差异(P<0.05),并在96 h达到最低值后保持稳定,盐度35组随处理时间的延长各离子浓度均上升,在120 h达到峰值;从渗透压的变化看,盐度5、10和15组中尿和血浆渗透压随盐度降低和处理时间的延长显著降低(P<0.05),而盐度35组尿和血浆渗透压随处理时间的延长而显著升高(P<0.05),渗透压在72 h后开始趋于稳定,在各处理时间点上均显著高于对照组(P<0.05);即在低盐度(5、10、15)下,随着时间的延长鳃丝Na-浓度变化看,盐度5、10、15组,在6～72 h内各离子浓度持续降低,整体上与对照组有显著性差异(P<0.05),并在96 h达到最低值后保持稳定,盐度35组随处理时间的延长各离子浓度均上升,在120 h达到峰值;从渗透压的变化看,盐度5、10和15组中尿和血浆渗透压随盐度降低和处理时间的延长显著降低(P<0.05),而盐度35组尿和血浆渗透压随处理时间的延长而显著升高(P<0.05),渗透压在72 h后开始趋于稳定,在各处理时间点上均显著高于对照组(P<0.05);即在低盐度(5、10、15)下,随着时间的延长鳃丝Na⁺/K+/K⁺-ATP酶活力,尿、血浆、血清中Na+-ATP酶活力,尿、血浆、血清中Na⁺、K+、K⁺、Cl+、Cl^-浓度,以及尿和血浆的渗透压均持续下降,上述大部分测定指标均在96 h后趋于稳定,而在高盐度(35)下各项指标总体呈上升的趋势;扫描电镜观察显示,与对照组相比,盐度5处理组的幼鱼鳃丝根部弯曲、小片粘连表面褶皱增多,皮肤分泌大量黏液物质,肾脏表皮露出大量颗粒状物质,而盐度35处理组损伤较轻。研究表明,黄条鰤幼鱼对盐度变化有较强的渗透调节能力,通过改变体液中离子含量及鳃丝Na-浓度,以及尿和血浆的渗透压均持续下降,上述大部分测定指标均在96 h后趋于稳定,而在高盐度(35)下各项指标总体呈上升的趋势;扫描电镜观察显示,与对照组相比,盐度5处理组的幼鱼鳃丝根部弯曲、小片粘连表面褶皱增多,皮肤分泌大量黏液物质,肾脏表皮露出大量颗粒状物质,而盐度35处理组损伤较轻。研究表明,黄条鰤幼鱼对盐度变化有较强的渗透调节能力,通过改变体液中离子含量及鳃丝Na⁺/K+/K⁺-ATP酶活力来调节渗透压以适应环境盐度的变化。     

Surveillance of levels in Gloucester Cathedral

A series of level measurements, over a period of 7 years, have been taken in Gloucester Cathedral to attempt to monitor vertical movement of the structure. A statistical regression analysis of the results showed that the Cathedral has tilted very slightly about an axis running approximately NNE to SSW. The heavy, bell tower end of the Cathedral has settled by 8 mm at some points although the general lowering is much less. Reasons for the change are probably because of changes in the water table. The statistical analysis showed that the errors followed a normal distribution.     

Lead levels in Birmingham dust

Dust is important as a factor affecting amenity and there are suggestions that it can make a significant contribution to the exposure of children to toxic materials and particularly to lead. The results are presented of an investigation into the lead concentrations in dust collected in Birmingham. Relationships are shown to exist between samples from similar areas and the distributions of lead concentrations throughout the City are shown. However, interpretations must be made with caution and this is illustrated by referring to some of the problems involved in the collection and chemical analysis of the samples.     

Pollution levels in some nigerian rivers

Surveys of five rivers in a hot-humid zone of a tropical country (Nigeria) were carried out over 3 years by obtaining samples for physical, chemical and bacteriological analyses. The main characteristics monitored were temperature, turbidity, total, dissolved and suspended solids, pH, dissolved oxygen, BOD, ammonia-nitrogen and the coliform counts. In addition, the main characteristics of the liquid waste being discharged into the rivers were determined.During the dry season, the highest mean temperature is 29°C with a range of 5°C and the lowest is 26°C with a range of 3°C. In the wet season, the highest mean temperature is 27.3°C with a range of 2°C while the lowest is 24.5°C with a range of 1°C. The other characteristics vary more widely with seasons. The high temperature in these rivers all the year round encourages pollution by human activities. During the dry season, pollution causes prolific algae boom, which causes oxygen supersaturation during periods of high temperature and abundant sunlight. The physical, chemical and biological characteristics of the rivers deteriorate sharply as they flow through towns and other human communities.     

Indoor natural radiation levels in Ireland

The principal results of a preliminary study made on indoor radiation levels in Ireland are presented. During the period 1983–1984 measurements were made in over 250 houses. Most measurements were made using passive devices: TLDs for penetrating radiation and CR-39 alpha track plastic detectors for radon measurements. The median value of the doses from penetrating radiation was 0.78 milligray/year with a maximum value of 1.47 m Gy/year detected. The radon concentrations showed a large degre of variability with a median value of 43 Bq/m³. About 10% of the houses had radon air concentrations in excess of 100 Bq/m³ with a maximum of 700 Bq/m³ being recorded. A tentative analysis of the data with regard to the geological situation is presented.     

Dental lead levels in Bombay inhabitants

Lead content in teeth of Bombay inhabitants has been measured. The lead concentration in teeth ranged from 4.27–82.5 μg/g of whole tooth with a geometrical mean concentration of 15.5 μg/g of tooth. There is no significant difference between the lead content in the teeth of males and females. The mean lead value is compared with those from other countries.     

Sweat lead levels in persons with high blood lead levels: lead in sweat of lead workers in the tropics

Samples of blood, sweat and urine were collected from eight control subjects and 19 lead workers in a battery manufacturing factory in the tropics. Sweat samples were collected while workers cycled on a bicycle ergometer at room temperature (27-31 degrees C). All samples were analysed by atomic absorption spectrophotometry. Workers with blood lead levels of 13-36 micrograms dl-1 had sweat levels of 72-256 micrograms l-1 and urinary levels of 28-288 micrograms/g creatinine, while controls had levels of 9-12.2 micrograms dl-1, 9-30 micrograms l-1 and 9-19.6 microgram/g creatinine, respectively. Estimations of sweat lead in lead workers can be masked by skin contamination.     

Background air levels of polychlorinated biphenyls in China

Measurements of the atmospheric concentrations of polychlorinated biphenyls (PCBs) were taken in 11 background sites geographically distributed throughout China. Active high-volume samplers were employed during two deployment periods between November 2007 and November 2008. 12 dioxin-like and 7 indicator PCBs were identified and measured. To keep the consistency, the two sampling periods were set in the same seasons (autumn and winter) and there were few variations between the results at all sites. The congener profile of indicator PCBs was dominated by CB28 and CB52. The most abundant mono-ortho congener was CB118, and the most abundant non-ortho congener was CB77. This study is the first systematic investigation into background atmospheric PCB levels in China. The background indicator ∑₇PCB levels in China are similar to those obtained at other background areas around the world.     

The relationship between perfluorinated chemical levels in the feathers and livers of birds from different trophic levels

Although feathers have been used successfully for monitoring heavy metals and organic pollutants, there are currently no data available on the use of feathers as indicators of perfluorinated chemical (PFC) exposure in birds. Also, no study has evaluated PFC levels in birds with different diets from different habitats. In the current study we investigated the PFC exposure of five different bird species from the same geographic region in Belgium, using both feathers and liver tissue. The highest mean liver perfluorooctane sulfonate (PFOS) levels were found in the Grey Heron (476 ng/g ww) followed by the Herring Gull (292 ng/g ww) and Eurasian Sparrowhawk (236 ng/g ww), whereas the Eurasian Magpie (17 ng/g ww) and the Eurasian Collared Dove (12 ng/g ww) had the lowest levels. The PFOS levels in the feathers showed a different pattern. The Grey Heron had the highest feather PFOS levels (247 ng/g dw), the Eurasian Sparrowhawk (102 ng/g dw) had the second highest feather PFOS levels, followed by the Herring Gull (79 ng/g dw) and the Eurasian Collared Dove (48 ng/g dw), and the lowest levels were found in the Eurasian Magpie (31 ng/g dw). Overall, there was a significant positive correlation (Pearson, R = 0.622, p < 0.01) between the feather and liver PFOS levels, indicating that feathers could be an alternative bioindicator for PFOS exposure in birds. However, caution should be taken as there was no significant correlation between the PFOS levels in the feathers and livers of the individual species. In general, birds from a higher trophic level had higher PFC levels in their tissues. This indicates that diet plays a role in PFC exposure in birds and confirms the bioaccumulation potential of PFC.     

Carboxyhemoglobin levels in blood donors in Bahrain.

A total of 107 venous blood samples were obtained from blood donors in Bahrain for carboxyhemoglobin (COHb) analysis. The donors were categorized according to their sex, smoking habits, occupation, place of work (indoor or outdoor), and residential area. The mean COHb levels were significantly higher in smokers (4.8%) than nonsmoking (1.5%). The mean COHb levels were higher in smoking, outdoor working donors (4.98%) and nonsmoking outdoor working donors (2.29%) than smoking indoor working donors (3.07%) and nonsmoking indoor working donors (1.04%). Other factors, such as sex and residential area did not influence COHb concentrations. The results indicate a possible influence of the levels of environmental carbon monoxide on the COHb in the blood of the Bahraini population.