Bulletin Board December 22, 2006

Environmental
Mercury content in electrum from artisanal mining site of

Mongolia

2006-11-30

In Mongolia, artisanal gold mining using Hg to extract gold, is becoming

very popular and the Hg contamination of mining site is becoming a serious

social issue. For the risk assessment of Hg, it is necessary to understand

how much Hg is introduced to the environment from what kind of materials

during mining activity. It is already known that major contribution of the

contamination comes from Hg that was bought at shops and brought to

mining sites by miners. However, no information is available on how much

Hg is removed from electrum (natural gold grain) to the environment. Since

gold deposit is always accompanied by Hg anomaly, it is anticipated that

electrum grains contain some amount of Hg of natural origin, and this Hg

(primary Hg) contributes to some extent to the contamination. To clarify how

much Hg is incorporated in electrum grains, micro-PIXE at CSIRO was used

for grain-by-grain analysis. Electrum from study area contains Hg e8260

ppm. For the risk management of Hg contamination, release of natural Hg

from electrum grains during smelting must not be ignored.

Authors: Murao, Satoshi; Naito, Kazuki; Dejidmaa, Gunchin; Sie, Soey H.

Full Source: Nuclear Instruments & Methods in Physics Research, Section B:

Beam Interactions with Materials and Atoms 2006, 249, 556-560 (England)
Mercury contamination in fish from gold mining areas in

Indonesia and human health risk assessment.

2006-11-30

This study investigated the effects on fish and assessed human health

hazards from mercury released in two gold mining areas in Indonesia:

Tatelu (North Sulawesi Province) and Galangan (Katingan District, Central

Kalimatan Province). In Tatelu, 154 fish specimens of 10 freshwater species

were collected, as well as five marine species from the fish market. The

mean concentration of total mercury in muscles of freshwater fish from

this area was 0.58 (0.44µg/g), with more than 45% of fish having Hg levels

above the WHO guideline for human consumption of 0.5 µg/g. In Galangan,

where 263 fish specimens of 25 species were collected, the total mercury

in muscles averaged 0.25 (0.69 µg/g). Excluding data from flooded open

pits in sub-area P4, mean Hg levels in fish from Galangan were 2 to 4 times

lower than 0.5 µg/g, while fewer than 10% of fish from Galangan exceeded

WHO guidelines. The Hazard Quotient (HQ) was applied to both areas

to determine the threat of MeHg exposure for communities in both areas.

The HQ is a risk assessment indicator, which defines the ratio of exposure

level to a single substance in relation to a reference dose. Samples from

Tatelu (excluding marine species) had an HQ above one, while those from

Galangan resulted in values of 2.4 for the whole area and 9.9 for sub-area

P4, pointing to potentially harmful fish consumption for the local population.

By using the single-compartment model to estimate mercury levels in blood

and hair from daily intake dose, sub-area P4 showed the highest levels,

higher than the upper limit guideline for pregnant women, but still lower than

threshold levels associated with observed clinical effects.

Authors: Castilhos, Zuleica C.; Rodrigues-Filho, Saulo; Rodrigues, Ana Paula

C.; Villas-Boas, Roberto C.; Siegel, Shefa; Veiga, Marcello M.; Beinhoff,

Christian.

Full Source: Science of the Total Environment 2006, 368(1), 320-325

(England).
Effect of different catalysts on the decomposition of

VOCs using flow-type plasma-driven catalysis

2006-11-30

This paper presented the effect of different catalysts on the decomposition

of benzene and toluene using flow-type plasma-driven catalyst (PDC)

system. Three representative materials of titanium dioxide, two types of

alumina and two zeolites were tested. Several types of metal catalysts

(Ag, Ni, Pt, Pd) and their loading amount were also investigated for the

optimisation of the PDC system. Three key factors of energy consumption,

carbon balance and safety of products were emphasized in evaluating the

performance of different catalysts. The type of catalysts greatly influenced

the carbon balance, CO2 selectivity, ozone formation, while not much

difference was observed in the degree of enhancement in energy efficiency.

The catalyst was found to be effective in enhancing the CO2 selectivity.

The CO2 selectivity increased as Ag-loading amount on TiO2 catalyst

increased. The 4.0 wt% Ag/TiO2 catalyst was effective in suppressing

the formation of NO2 and N2O. Zeolites showed comparable decomposition

efficiency and good carbon balance, while the CO2 selectivity was poor

compared to the other catalysts.

Authors: Kim, Hyun-Ha; Ogata, Atsushi; Futamura, Shigeru

Full Source: IEEE Transactions on Plasma Science 2006, 34(3, Pt. 3), 984

-995 (England).

Medical
Organophosphorus chemicals: Potent inhibitors of the

human metabolism of steroid hormones and xenobiotics

2006-11-30

Although it has been known for some time that organophosphate chemicals

containing the P S moiety are irreversible inhibitors of cytochrome P 450,

this knowledge has not been generally applied to the human metabolism of

xenobiotics.

Recent studies have demonstrated that organophosphate insecticides

containing this moiety are potent inhibitors of the metabolism of both

xenobiotics and endogenous substrates by human liver microsomes and by

specific human cytochrome P 450 isoforms.

Authors: Hodgson, Ernest; Rose, Randy L.

Full Source: Drug Metabolism Reviews 2006, 38(1-2), 149-162 (England)
Comparative evaluation of the Cu, Zn, Pb, and Cd content

in healthy people and patients with oncological diseases

of the blood

2006-11-30

Inversion voltammetry was used to study blood and urine levels of Cu, Zn,

Pb, and Cd in 52 healthy people and 28 patients with Hodgkin’s lymphoma

(HL). Blood and urine levels of Zn, Pb, and Cd in healthy people did not

differ from accepted norms, but the Cu content of blood and blood fractions

was at the lower boundary of normal. The content of Cu in whole blood of

HL patients differed from normal, there being a disruption of the balance

between Cu and Zn in blood and urine. There was a clear deficit of Zn in

blood and an excess in urine. In all HL groups there was a deficiency in

excretion of Cd and a deficit of Pb in the blood as compared with healthy

controls.

Authors: Zakharchuk, N. F.; Soldatova, G. S.; Novikova, T. V.; Borisova, N.

S.

Full Source: Khimiya v Interesakh Ustoichivogo Razvitiya 2006, 14(3), 251-

261 (Russia)
Mass balance study of persistent perfluorinated

chemicals in human blood

2006-11-30

Studies of occurrence of persistent perfluorinated chemicals (PFCs), such

as PFOS and PFOA, in human blood have received considerable public

concern due to the potential risks of these compounds to human health.

In spite of a number of reports about the occurrence of individual PFCs in

human blood, very little information is available on total organic fluorine (TOF)

residues in biological matrixes. Measurement of TOF in biological matrixes

was hindered by the lack of appropriate and sensitive analytical techniques.

In this study, a new method was developed for measuring TOF at sub-part per

billion levels and this method was applied to several blood samples collected

from the United States and Asian countries. Contributions of known PFCs

in the human blood samples were around a few percentage relative to total

fluorine, but the major part of the organic fluorine was extractable by ion-pair

extraction solvents. There were significant differences in the composition of

organic fluorine between people with elevated (occupational) exposures and

the control group. Results of relative contribution of individual PFCs to total

organic fluorine were discussed in the light of the mass balance approach of

both inorganic and organic fluorine.

Authors: Miyake, Yuichi; Kannan, Kurunthachalam; So, Man Ka; Taniyasu,

Sachi; Lam, Paul K. S.; Yamashita, Nobuyoshi

Full Source: Preprints of Extended Abstracts presented at the ACS

National Meeting, American Chemical Society, Division of Environmental

Chemistry [computer optical disk] 2006, 46(2), 869-873 (England)
Abnormal expression of eukaryotic translation factors in

malignant transformed human bronchial epithelial cells

induced by crystalline nickel sulfide

2006-11-30

The oncogenic potential of mouse translation initiation factor 3 (TIF3)

and elongation factor-∂ (TEF-∂) was studied in malignant transformed

human bronchial epithelial cells induced by crystalline nickel sulfide (NiS).

Abnormal expressions of human TIF3 and TEF-∂ genes in two kinds of

NiS-transformed cells and NiS-tumorigenic cell lines were investigated and

analyzed by the reverse transcript polymerase chain reaction (RT-PCR) and

fluorescent quantitative polymerase chain reaction (FQ-PCR), respectively.

RTPCR analysis primarily showed that both human TIF3 and TEF-∂ mRNA

expressions in two kinds of NiS-transformed cells and NiStumorigenic cell

lines were increased as compared with controls. FQPCR assay showed that

the levels of TIF3 expressions in the transformed cells and tumorigenic cells

were 3 and 4 times higher respectively, and the elevated expressions of TEF-

∂ cDNA copies were 2.7- to 3.5-fold in transformed cells and 4.1- to 5.2-fold

in tumorigenic cells when compared with non-transformed cells, indicating

that the over-expressions of human TIF3 and TEF-∂ genes were related to

malignant degree of the cells induced by nickel. These findings demonstrate

that there are markedly abnormal expressions of TIF3 and TEF-∂ genes

during malignant transformation of human bronchial epithelial cell lines

induced by crystalline NiS. They seem to be the molecular mechanisms

potentially responsible for human Carcinogenesis due to nickel.

Authors: Lei, Yi-Xiong; Chen, Xue-Min; Wu, Gen-Rong; Chen, Jia-Kun

Full Source: Biomedical and Environmental Sciences 2006, 19(1), 53-60

(England)
Ferric iron increases ROS formation, modulates

cell growth and enhances genotoxic damage by 4-

hydroxynonenal in human colon tumor cells

2006-11-30

Fe is a relevant risk factor for colorectal cancer due to its genotoxic properties.

The researchers hypothesized that Fe-overload caused other toxic effects,

which contribute to carcinogenesis. They investigated formation of reactive

oxygen species (ROS), DNA repair, cell growth and glutathione (GSH) in

human colon tumor cells (HT29 clone 19A) treated with ferric nitrilotriacetate

(Fe-NTA, 0-2000 µM). Intracellular formation of ROS was analysed with

the peroxide-labile fluorescent dye carboxy-dichlorodihydrofluorescine-

diacetate. DNA repair, reflected as the persistency of DNA damage induced

by selected genotoxins, was determined with the Comet assay. Cell growth

and GSH were measured by fluorimetrical analysis. Key findings were that

ROS formation increased with time (1000 µM Fe-NTA, p < 0.001). DNA

damage was largely repaired after 120 min, but was not affected by 10 µM

Fe-NTA. In contrast, 10 µM Fe-NTA significantly increased DNA damage

induced by 4-hydroxynonenal. Doses of 25 µM Fe- NTA increased cell

growth, whereas high concentrations (2000 µM) resulted in growth arrest,

which was accompanied by increased GSH levels. In conclusion, high

concentrations of Fe- NTA caused cellular effects, which reflect a stress

response, and resulted in formation of ROS. Carcinogenic risks from Fe3+

could be derived also from lower concentrations, which enhance tumor cell

growth and cause progenotoxic effects.

Authors: Knoebel, Y.; Glei, M.; Osswald, K.; Pool-Zobel, B. L.

Full Source: Toxicology in Vitro 2006, 20(6), 793-800 (England)

Occupational
Personal exposure of Parisian office workers to benzene

2006-11-29

Currently in France there is only data from a few studies available on the

exposure of Parisian office workers to benzene and these levels were

measured prior to the new regulation on benzene in gasoline, which came

into force in 2000. This study investigated the personal exposure of a

randomized sample of 100 non-smoking Paris office workers to benzene

and then to identify and quantify their micro-environmental determinants,

24-h samplings took place between June 2000 and June 2001. Each

participant was equipped with two active devices in order to assess total

personal exposure over 24 h and exposure during transportation. Inhouse

and in-office fixed measurements were performed only when the subject was

present in these microenvironments. Benzene was collected on a sorbent

tube, thermally desorbed and analyzed by gas chromatography and flame

ionization detection. A questionnaire was also completed by the subjects

regarding residential and occupational environments, mean of transportation

used and time activity patterns during the 24-h sampling period. The

researchers found that the average benzene personal exposure was 4.6.

the highest levels of benzene were observed during transportation. Linear

multiple regressions showed that inhouse, in office and in-transit exposures

explained 95% of variations in personal exposure to benzene. The authors

concluded that the direct and indirect methods used to assess personal

exposure to benzene are in agreement; with only a few measurements

showing noticeable differences in relation to atypical situations.

Authors: Dusseaux, Murielle; Laurent, Anne-Marie; Le Moullec, Yvon;

Person, Alain; Momas, Isabelle

Full Source: Pollution Atmospherique 2005, (Spec.), 87-91 (Eng)
Biomonitoring of exposure in farm worker studies

2006-11-29

The complexities and uncertainties involved in the biomonitoring process

are only just beginning to be understood despite the process being used

in many occupational and environmental health and exposure studies.

This paper provides an overview of concepts that should be considered

when using biomonitoring or biomonitoring data, assess the current status

of biomonitoring, and detail potential advancements in the field that may

improve our ability to both collect and interpret biomonitoring data. Issues

such as the appropriateness of biomonitoring for a given study, the sampling

timeframe, temporal variability in biological measurements to non-persistent

chemicals, and the complex issues surrounding data interpretation are

discussed. In addition, the authors provide recommendations to improve the

utility of biomonitoring in farm worker studies.

Authors: Barr, Dana B.; Thomas, Kent; Curwin, Brian; Landsittel, Doug;

Raymer, James; Lu, Chensheng; Donnelly, K. C.; Acquavella, John

Full Source: Environmental Health Perspectives 2006, 114(6), 936-942

(Eng)
Personality traits in miners with past occupational

elemental mercury exposure

2006-11-29

This study evaluated the impact of long-term occupational exposure to

elemental mercury vapor (Hg0) on the personality traits of ex-mercury

miners. Study groups included 53 ex-miners previously exposed to Hg0 and

53 age-matched controls. Miners and controls completed the self-reporting

Eysenck Personality Questionnaire and the Emotional States Questionnaire.

The relationship between the indexes of past occupational exposure and

personality traits were evaluated using Pearson’s correlation coefficient

and on a subgroup level by machine learning methods (regression trees).

Ex-mercury miners were intermittently exposed to Hg0 for a period of 7-31

years and the result showed mean exposure-cycle urine mercury (U-Hg)

concentrations ranging from 20 to 120 µg/L. In addition the researchers found

that ex-miners tended to be more introverted and sincere, more depressive,

more rigid in expressing their emotions and are likely to have more negative

self-concepts than controls. However, there no correlations found with the

indexes of past occupational exposure. There was some limitation to the

results received via the regression tree analysis. Higher alcohol consumption

and long-term intermittent, moderate exposure to Hg0 remain a plausible

explanation for the depression associated with negative self-concept found

in subgroups of ex-mercury miners. The authors concluded that these

findings may suggest why there is a higher risk of suicide among miners of

the Idrija Mercury Mine in the last 45 years.

Authors: Grum, Darja Kobal; Kobal, Alfred B.; Arneric, Niko; Horvat, Milena;

Zenko, Bernard; Dzeroski, Saso; Osredkar, Josko

Full Source: Environmental Health Perspectives 2006, 114(2), 290-296

(Eng)
Studying health outcomes in farm worker populations

exposed to pesticides

2006-11-29

One of the goals of studying farm workers is to have a better understanding

of how their work environment, including exposure to pesticides, affects their

health. While pesticide exposure has been linked to a number of health

conditions, no clear relationship between exposure and health effects have

been found except in cases of acute pesticide exposure. This study reviewed

the most common health end points that have been studied and described

the epidemiological challenges encountered in studying these health effects

of pesticides among farm workers, including the difficulties in accessing the

population and challenges associated with obtaining health end point data.

Neurobehavioral effects are the most common approaches used to determine

the health outcomes in farm workers and other populations exposed to

pesticides. The authors review the limitations in the current neurobehavioral

assessment and strategies needed to improve these analytical methods.

Emerging techniques to improve assessment of health effects associated

with pesticide exposure are also reviewed. The authors concluded that

these techniques, which in most cases have not been applied to farm

worker populations, hold promise in our ability to study and understand the

relationship between pesticide exposure and a variety of health effects in

this population.

Authors: McCauley, Linda A.; Anger, W. Kent; Keifer, Matthew; Langley,

Rick; Robson, Mark G.; Rohlman, Diane

Full Source: Environmental Health Perspectives 2006, 114(6), 953-960

(Eng)
Short-term respiratory effects of cleaning exposures in

female domestic cleaners

2006-11-29

Previous studies have found that symptoms of obstructive lung disease in

domestic cleaners are related to the use of bleach and other irritant cleaning

products. This study investigated the short-term effects of cleaning exposures

on respiratory symptoms and peak expiratory flow (PEF) in domestic cleaners

with respiratory disorders. 43 female domestic cleaners with a recent history

of asthma and/or chronic bronchitis completed a 2-wk diary, collecting

information on respiratory symptoms, PEF and cleaning exposures. Mixed

regression models were used to assess daily changes in symptoms and

PEF associated with specific cleaning exposures. The results showed that

lower respiratory tract symptoms were more common on working days and

were predominantly associated with exposure to diluted bleach, degreasing

sprays/atomisers and air fresheners. Associations with upper respiratory

tract symptoms and PEF were less apparent. Eleven (30%) subjects scored

positive for work-related asthma. The authors concluded that exposure to

certain irritant cleaning products aggravates lower respiratory tract symptoms

in female domestic cleaners with asthma or chronic bronchitis.

Authors: Medina-Ramon, M.; Zock, J. P.; Kogevinas, M.; Sunyer, J.;

Basaggana, X.; Schwartz, J.; Burge, P. S.; Moore, V.; Anto, J. M.

Full Source: European Respiratory Journal 2006, 27(6), 1196-1203 (Eng)