Tbiosorbents Used for Organic and Metallic Pollutiontreatment

ENVIRONMENTAL

~dEnvironmental

~tBiosorbents Used for Organic and Metallic PollutionTreatment

~w2009-10-18

The organic and metallic pollutionof water resources is constantly growing in the African cities. In Coted'Ivoire, the industrial and human activities are essentially responsible for this phenomenon. For instance, industries such as coating, electricalbattery manufacturing, paint, lead smelting, internal combustion engines,generates large quantity of wastewaters containing large quantity of lead,zinc, iron, copper etc. These metals are potentially toxic as reportedby many authors. So their removal from industrial wastewatersremains an important challenge for researchers. Water pollution withorganic matter fermenting led to the loss of dissolved oxygen. Thiscauses the death of aquatic life and other animals in these waters.The presence of nutrients such as phosphorus is also responsible for the eutrophication characterised by the growth of watery plants. Thetreatment of the wastewaters via conventional methods remainsexpensive for the third word country. Fortunately, alternative pathwaysbased on the use of biomaterials available in large quantitiesand inexpensive, particularly biosorbents are increasingly attractive.The work presented here concerns the use of activated carbon frommesocarpe fibrous of coconut, seed hull of the palm tree, Tieghemellaheckelii on the one hand and the use pterygota macrocarpa sawdustand clays on the other hand for the heavy metal and org. pollutionremoval from wastewaters. The influences of different parameterssuch as absorbent dose, pH, temp., contact time and initial pollutant concentration are studied. Kinetic and thermodynamic aspects are also discussed.The use of mesocarpe fibrous of coconut showed a COD fall rate goingfrom 84 to 94%. Concerning the metal ion uptake, the use of activatedcarbon from, seed hull of the palm tree and Tieghemella heckelii gavewhatever the operating conditions, a pollutant elimination higher than80%. Moreover, the equivalentstudies showed that the sorption processeswere best fitted by the Langmuir and Freundlich models.

Authors: Yao, Benjamin; Adouby, Kopoin; Dadle, Pierre; Briton, Henry Bi; Gueu, Soumahoro

Full Source: Progress in Environmental Science and Technology 2009, 2(Pt. B),1064-1068 (English)

~dEnvironmental

~tHeavy metal contamination of paddy soils andrice(Oryza sativa L.) from Kocani Field (Macedonia)

~w2009-10-18

Heavy metal contamination of the paddy soils and ricefrom Kocani Field (eastern Macedonia) resulting from irrigation byriverine water impacted by past and present base-metal miningactivities and acid mine drainage was studied. Very high concentrations ofAs, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99,983 and 1,245 íg g-1) and the rice (0.53, 0.31, 5.8, 0.5 and 67 íg g-1)in the western part of Kocani Field, close to the Zletovska River,which drains the mining facilities of the Pb-Zn mine in Zletovo. In terms of health risk, the observed highest concentrations of these elements inthe rice could have an effect on human health and should be thesubject of further investigations.

Authors: Rogan, Nastja; Serafimovski, Todor; Dolenec, Matej; Tasev, Goran; Dolenec, Tadej

Full Source: Environmental Geochemistry and Health 2009, 31(4), 439-451 (Eng)

MEDICAL

~dMedical

~tEffect of trichloroethylene on nitric oxide synthesisand cell activity of human keratinocytes

~w2009-10-18

The effect of trichloroethylene (TCE) on nitricoxide (NO) and cell activity in human keratinocytes (KC) was observed,and the mechanism of dermatotoxicity caused by TCE was furtherexplored. Cultured human keratinocytes were exposed to 0, 0.125,0.25, 0.5, 1.0 and 2.0 mmol/L TCE for 4 h with or without the 30 minpre-treatment with 100 mmol/L aminoguanidine (AG), which is a specific inhibitorof inducible nitric oxide synthase (iNOS). After 12 h, 24 h, 48 hand 72 h incubation, the NO concentration in the mediums was detected,and the cell viability was detected by MTT test as well. It was shownthat there was no obvious increase in NO level when KC treated with lower concentration of TCE such as 0.125 mmol/L and 0.25 mmol/L (P<0.05,compared with the controls); while TCE of higher dose (such as 0.5to 2.0 mmol/L) might induce the rise of NO level (P<0.05); andmeanwhile, cell viability was also markedly decreased. The pre-treatment with AG might effectively lower the rise of NO level in higherdosage groups, especially at 48 h, and the cell viabilities were also restoredto baseline levels. TCE can induce keratinocytes to produce NO inthe dose- and time-dependent manner, and the overdose of NO mayplay a role in the cytotoxicity of TCE on keratinocytes.

Authors: Ye, Liangping; Wang, Lijie; Shen, Tong; Zhu, Qixing

Full Source: Zhongguo Gongye Yixue Zazhi 2008, 21(2), 79-81 (Ch)

~dMedical

~tGenotoxicity of organoselenium compounds inhuman leukocytes in vitro

~w2009-10-18

DNA damage andcell viability of human leukocytes cells were examined as simple testsfor screening the potential toxicity of organoselenium compounds. Leukocyteswere incubated with different organoselenium compounds at 4,10, 40 and 100 mM or vehicle (DMSO) for 3 h at 37 °C before invitro assays. Cell viability was determined by Trypan blue exclusion. DNAdamage was assessed using the alkaline comet assay with silver staining.The exposure of leukocytes to (S)-tert-Bu 1-diselenide-3-methylbutan-2-ylcarbamate, (S)-tert-Bu 1-diselenide-3-phenylpropan-2-ylcarbamate, (S)-2-amino-1-diselenide-3-methylpropanyl, (S)-2-amino-1-diselenide-3-phenylpropanyl, 3',3-ditrifluoromethyldi-Ph diselenide, 4',4-dimethoxy di-Ph diselenide, 4',4-dichloro di-Ph diselenide and 2',2,4',4,6',6-hexamethyl di-Ph diselenide, in therange of 10-100 mM, induced a significant increase in Damage Index(DI). The genotoxic effect of all compounds was associated with high frequenciesof cells with damage level 4 and all compounds caused a decreasein cell viability. These results suggest that the selenium compounds tested were genotoxic and cytotoxic to human leukocytes cells in vitroand that the organoselenium amino acid derivatives.((S)-tert-Bu 1-diselenide-3-methylbutan-2-ylcarbamate, (S)-tert-Bu 1-diselenide-

3-phenylpropan-2-ylcarbamate, (S)-2-amino-1-diselenide-3-methylpropanyl and (S)-2-amino-1-diselenide-3-phenylpropanyl) were more genotoxic than aromatic derivatives (3',3-ditrifluoromethyl di-Ph diselenide, 4',4-dimethoxy di-Ph diselenide, 4',4-dichloro di-Ph diselenide and 2',2,4',4,6',6-hexamethyl di-Ph diselenide). Theseeffects may be linked to the pro-oxidant activity exhibited by seleniumcompounds when used in relatively high concentrations.

Authors: Santos, D. B.; Schiar, V. P. P.; Ribeiro, M. C. P.; Schwab, R. S.; Meinerz, D. F.; Allebrandt, J.; Rocha, J. B. T.; Nogueira, C. W.; Aschner, M.; Barbosa, N. B. V. Full Source: Mutation Research, Genetic Toxicology and Environmental Mutagenesis

2009, 676(1-2), 21-26 (Eng)

~dMedical

~tA Human PBPK/PD Model to Assess ArsenicExposure Risk Through Farmed Tilapia Consumption

~w2009-10-18

The purpose of this study was to develop a biological based riskassessment model for human health through consumption of arsenic(As) contaminated farmed tilapia (Oreochromis mossambicus) fromblackfoot disease (BFD)-endemic area in Taiwan for estimating the consumption advice. We linked a physiological based pharmacokinetic (PBPK)and a pharmacodynamic (PD) model to account for the exposure anddose-response profiles of As in human. Risk analysis indicates thatconsumption of farmed tilapia poses no significant threat from Asinducedlung and bladder cancers. The predicted risk-based medianconsumption advice was no more than 5-17 meals month-1 (or 2-6g/day).

Authors: Ling, M.-P.; Liao, C.-M.

Full Source: Bulletin of Environmental Contamination and Toxicology 2009, 83(1), 108-114 (Eng)

~dMedical

~tFluoride-induced cyclooxygenase-2 expressionand prostaglandin E2 production in A549 human pulmonaryepithelial cells

~w2009-10-18

To clarify the mechanisms of fluoride-induced airway diseases, the authors examined the expression of cyclooxygenase-2(COX-2), an important mediator of airway inflammation, in A549human pulmonary epithelial cells treated with sodium fluoride (NaF).Following exposure to 5 mM NaF, COX-2 protein and COX-2transcript increased markedly. However, no change was observed inCOX-1 expression. NaF-induced accumulation of COX-2 transcriptwas abolished by actinomycin D, but not cycloheximide. The level ofprostaglandin E2, a major product of COX enzymes, increased inresponse to NaF exposure, and its production was abolished by the selectiveCOX-2 inhibitor NS-398. Phosphorylated forms of mitogenactivatedprotein kinases (MAPKs)-including extracellular signal-regulatedprotein kinase (ERK), c-Jun NH2-terminal kinase, andp38-increased after NaF exposure, while treatment with theMAPK/ERK kinase inhibitor U0126 and the p38 inhibitor SB203580markedly suppressed COX-2 expression. Furthermore, NaF-inducedCOX-2 expression was markedly suppressed by the Src family kinase(SFK) inhibitor PP2, but only partially suppressed by theepidermal growth factor receptor (EGFR) inhibitor PD153035. Apparently,NaF induces COX-2 expression by transcriptional upregulationvia p38 and ERK pathways, at least in part, and SFKsmay be upstream tyrosine kinases responsible for NaF-inducedCOX-2 expression in A549 cells.

Authors: Ridley, Wakako; Matsuoka, Masato

Full Source: Toxicology Letters 2009, 188(3), 180-185 (Eng),

~dMedical

~tReverse Type I Binding Spectra of Human CytochromeP450 1B1 Induced by Flavonoid, Stilbene, Pyrene,Naphthalene, Phenanthrene, and Biphenyl Derivatives ThatInhibit Catalytic Activity: A Structure-Function RelationshipStudy

~w2009-10-18

Fifty-one chemicals including derivatives of 16 flavonoids, three stilbenes, six pyrenes, seven naphthalenes,seven phenanthrenes, 10 biphenyls, 17â-estradiol, and estrone were examined for their abilities to induce reverse type I binding spectrawith human cytochrome P 450 1B1 and to inhibit 7-ethoxyresorufinO-deethylation (EROD) activities catalysed by P 450 1B1. Fortynine chemicals showed reverse type I spectra with P 450 1B1, and theauthors found that 3,5,7-trihydroxyflavone, 3',4'-dimethoxy-5,7-dihydroxyflavone, 4'-methoxy-5,7-dihydroxyflavone, R- and â-naphthoflavones,2,4,3',5'-tetramethoxystilbene, pyrene, and several acetylenicpyrenes and phenanthrenes were strong inducers of the spectraand also potent inhibitors of EROD activities catalysed by P 450 1B1.The spectral dissociation constant (Ks) and the magnitude of the binding (¢Amax/Ks) of 49 chemicals were correlated with the inhibition potenciesof EROD activities by these chemicals [correlation coefficients (r) of 0.72 and 0.74, respectively. The Ks and ¢Amax/Ks values were more correlated withIC50 values when compared in a group of derivatives of flavonoids, stilbenes,and oestrogens (r ) 0.81 and 0.88, respectively) or a group of derivatives of pyrenes, naphthalenes, phenanthrenes, and biphenyls (r) 0.88 and 0.91, respectively). Among 14 flavonoids examined, 3,5,7-trihydroxyflavoneand 4'-methoxy- and 3',4'-dimethoxy-5,7-dihydroxyflavonewere more active than flavone in interacting with P 450 1B1, but the respectively 7,8-dihydroxyflavones were less active. Pyrene itselfwas highly active in interacting with P 450 1B1, but its binding wasslightly decreased when substituted with acetylenic groups. Incontrast, substitution of naphthalene with Me and Et propargyl ethersled to more interaction with P 450 1B1 than with naphthalene itself.Similarly, substitution on phenanthrene or biphenyl with acetylenicgroups and propargyl ethers increased affinities to P 450 1B1. Theseresults suggest that the reverse type I binding of chemicals to P 450 1B1 may determine how they interact with and inhibit the catalytic activity ofthe enzyme. Substitutions on the compounds with various acetylenicgroups and propargyl ethers cause an increase or decrease of theiraffinities to P 450 1B1, depending on the parent compound used.

Authors: Shimada, Tsutomu; Tanaka, Katsuhiro; Takenaka, Shigeo; Foroozesh, Maryam K.; Murayama, Norie; Yamazaki, Hiroshi; Guengerich, F. Peter; Komori, Masayuki

Full Source: Chemical Research in Toxicology 2009, 22(7), 1325-1333(Eng)

OCCUPATIONAL

~dOccupational

~tOccupational hazards identification and analysis in electronic assembly industry

~w2009-10-25

Based on the Chinese occupational hazards classification lists and occupational disease causationmodels, the occupational hazards existing in theelectronic assembly industry were analysed in this study and identified according tothe features of materials, equipment and staffs in DIP and QFP/SOICproduction process. Based on the findings, the authors concluded that emphasis should be put on theprevention and control of silicon or silicon dioxide dusts, lead, argon gas, high temperature, epoxy resin, potassium hydroxide, noise, acid mist,repeatable static work and dynamic work. Theseresults provide basicsupport for the quantitative risk assessment of occupational hazards andthe establishment of occupational hazard protection measures in theelectronic assembly industry.

Authors: Tian, Meng; Ye, De-hong; Zhao, Chang-sheng

Full Source: Zhongguo Anquan Kexue Xuebao 2008, 18(7), 161-165 (Ch)

~dOccupational

~tRadon and risk of extrapulmonary cancers:results of the German uranium miners' cohort study, 1960-2003

~w2009-10-25

In this study, the authors analysed data from the German miners' cohort study in order to determine whether radon in ambient air causes cancers otherthan lung cancer. The cohort includes 58 987 men who were employedfor at least 6 months from 1946 to 1989 at the former Wismut uraniummining company in Eastern Germany. A total of 20 684 deaths wereobserved in the follow-up period from 1960 to 2003. The death rates for24 individual cancer sites were compared with the age and calendaryear-specific national death rates. Internal Poisson regression wasused to estimate the excess relative risk (ERR) per unit of cumulativeexposure to radon in working level months (WLM). The results demonstrated that the number of deaths observed (O) for extrapulmonary cancers combined was close to thatexpected (E) from national rates (n)3340, O/E)1.02; 95% confidenceinterval (CI): 0.98-1.05). Statistically significant increases in mortalitywere recorded for cancers of the stomach (O/E)1.15; 95% CI:1.06-1.25) and liver (O/E)1.26; 95% CI: 1.07-1.48), whereas significantdecreases were found for cancers of the tongue, mouth, salivarygland and pharynx combined (O/E)0.80; 95% CI: 0.65-0.97) and thoseof the bladder (O/E)0.82; 95% CI: 0.70-0.95). the authors detected a statistically significantrelationship between the cumulative radon exposure for allextrapulmonary cancers (ERR/WLM)0.014%; 95% CI: 0.006-0.023%).Most sites showed positive exposure-response relationships, but thesewere insignificant or became insignificant after adjustment for potentialconfounders such as arsenic or dust exposure. In conclusion, the findings from this study provide some evidence of increased risk of extrapulmonary cancersassociated with radon, but chance and confounding cannot be ruled out.

Authors: Kreuzer, M.; Walsh, L.; Schnelzer, M.; Tschense, A.; Grosche, B.

Full Source: BritishJournal of Cancer 2008, 99(11), 1946-1953 (Eng)

~dOccupational

~tStudy on the determination of the time weightedaverage concentration for styrene in workplace air

~w2009-10-25

In this study, a gas chromatography method was established to determine the TWA concentration of styrene in work place air.Styrene solvent was sampled with active carbon tube, and styrene inthe air was detected using solvent desorption with carbon disulphide. Themethod is based on the standardisation of methods for detection of toxicsubstances in workplace air. The detection and chromatography conditions were optimised. The linear limit of the methods was at the range of2.6-1,000íg/mL, the coefficient of correlation was 0.9997, the limit of detectionof the solvents was 2.6íg/mL, and the coefficient of variation in sampledetection was ranged from 3.1% to 5.6%. The breakthrough capacity oflO Omg active carbon for the solvent was 28.6mg, and the samplecould be stably stored in the active carbon tube for at least 7 days.This method corresponded to the Chinese guidelines for the methodfor detection of toxic substances in workplace air. The authors concluded that the method was successfully establishedand was proven to be suitable for detection of the TWA concentration ofstyrene in workplace air, which makes contribution to putting thenew limit of occupational exposure into practice.

Author: Wang, Xian-yi

Full Source: Xiandai Yufang Yixue 2008, 35(20), 3927-3928 (Ch)

~dOccupational

~tAirborne Monitoring to Distinguish EngineeredNanomaterials from Incidental Particles for Environmental Health and Safety

~w2009-10-25

In this study, the authors used two methods to distinguish airborne engineered nanomaterials from other airborne particlesin a facility that produces nano-structured lithium titanate metaloxide powder. The first method involved off-line analysis of filtersamples collected with conventional respirable samplers at each ofseven locations (six near production processes and one outdoors). Throughoutmost of the facility and outdoors, respirable mass concentrations werelow (<0.050 mg/m3) and were attributed to particles other than thenanomaterial (<10% by mass titanium detected with inductively coupledplasma atomic emission spectrometry). In contrast, in a single area withextensive material handling, mass concentrations were greatest (0.118 mgm-3) and contained up to 39% ( 11% lithium titanium, indicating thepresence of airborne nanomaterial. Analysis of the filter samples collectedin this area by transmission electron microscope and scanningelectron microscope revealed that the airborne nanomaterial was associated only with spherical aggregates (clusters of fused 10-80 nm nanoparticles)that were larger than 200 nm. In addition, this analysis showed thatnanoparticles in this area were the smallest particles of a largerdistribution of submicrometre chain agglomerates likely from weldingin an adjacent area of the facility. The second method used two,hand-held, direct-reading, battery-operated instruments to obtaina time series of very fine particle no. (<300 nm), respirable mass, andtotal mass concentration, which were then related to activities within thearea of extensive material handling. This activity-based monitoringshowed that very fine particle number concentrations (<300 nm) had no apparentcorrelation to worker activities, but that sharp peaks in the respirableand total mass concentration coincided with loading a hopper and replacingnanomaterial collection bags. The authors concluded that the findings from the study were consistent withthose from the filter-based method in that they demonstrate thatairborne nanoparticles in this facility are dominated by "incidental"sources (e.g., welding or grinding), and that the airborne "engineered"product is predominately composed of particles larger than severalhundred nanometers. The methods presented here are applicable toany occupational or environmental setting in which one needs todistinguish incidental sources from engineered product.

Authors: Peters, Thomas M.; Elzey, Sherrie; Johnson, Ronald; Park, Heaweon; Grassian, Vicki H.; Maher, Tabitha;O'Shaughnessy, Patrick

Full Source: Journal of Occupational and Environmental Hygiene 2009, 6(2), 73-81 (Eng)

~dOccupational

~tAn epidemic of silicosis among former denim sandblasters

~w2009-10-25

Sandblasting denim using silica has emerged as a new cause of silicosis in Turkey. Following the discovery of several cases ofsilicosis in (young) workers who used this process, the frequency andmain occupational risk factors of silicosis among former denim sandblastersin the region of Erzurum (Turkey) were evaluated. The authors obtained demographic characteristics and information on working conditions via questionnaire and interview. In addition, spirometry testing was conducted and chest radiographs were evaluated according to InternationalLabour Office (ILO) classification of pneumoconiosis in 157former denim sandblasters. All subjects were male, with a mean(range) age of 23 (15-44) yrs. They had worked for a mean (range)of 36 (1-120) months, starting employment at a 17 (10-38) yrs ofage. Most subjects (83%) had respiratory symptoms, especially dyspnea(52%) but also chest pain (46%). Radiological evidence of silicosis (ILOscore 1/0 or higher) was present in 77 (53%) out of 145 subjects withinterpretable chest radiographs. These subjects had lower forcedexpiratory volume in one second and forced vital capacity. The risk ofsilicosis correlated with seniority (i.e. working as a foreman), exposure duration and number of places of work. The authors concluded that considering the high prevalencerate of silicosis in such workplaces, further problems are inevitablein the future unless effective measures are taken.