Duration of exposure to environmental carcinogens affects DNA-adduct level in human lymphocytes

Background and objective: An important issue in human biomonitoring is determining how exposure duration affects the kinetics of molecular biomarkers. In this study we compare the influence of exposure variables on DNA adducts.

Methods: DNA adducts were analysed by 32P-postlabelling in lympho/monocytes of 677 Caucasian subjects.

Results: After correction for other variables, DNA adducts increased depending on the length of occupational and smoke exposures. Higher DNA adducts were detected in workers with more than 14 years of exposure than in workers with shorter exposures (RR?=?1.19, p?=?0.049) and in smokers with more than 10 years of exposure than in smokers with shorter exposure (RR?=?1.21, p <0.001).

Conclusions: Exposure length is the primary factor affecting DNA-adduct level in lympho/monocytes both in smokers and in occupationally exposed subjects.     

Occupational exposure of foundry workers assessed by the urinary concentrations of 18 elements and arsenic species

BackgroundSome raw materials applied in Fe foundry industries may contain potentially toxic elements. Thus, foundry worker’s occupational exposure is a constant health concern.MethodIn this study, 194 urine samples from foundry workers were analyzed by inductively coupled plasma mass spectrometry for biomonitoring of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, I, Mn, Ni, Pb, Sb, Sn, Se, U and Zn. Moreover, arsenic speciation was performed in representative samples of production sector workers (group A) and administration sector workers (group B).ResultsConcentrations of As, Pb, Cd, Cu, Cs, I, Sb in urines from group A were higher than those found for group B. Samples of group A presented Cs, Ni, Mn, Pb, U and Zn concentrations higher than values reported for exposed workers assessed by other studies. Forty-four samples from group A exceed As-reference limits. Group A had approximately seven times more inorganic As (as arsenite) and 14 times more organic As (as dimethyl As) than group B. A statistically significant difference was observed in the elemental concentration in the workers' urine by the time in the function. Moreover, alcohol consumption is probably influencing the urine concentration of As, Ba, Cd, Co, Cu, Fe, I, Se and Zn.ConclusionThe monitored foundry workers are exposed to potentially toxic elements and more attention must be given to their health. Therefore, workplace safety conditions must be improved, and constant biomonitoring is necessary to ensure workers' health.     

Biochemical alterations induced by nickel oxide nanoparticles in female Wistar albino rats after acute oral exposure

Context: Nickel oxide (NiO) nanoparticles (NPs) with appropriate surface chemistry have been widely used for their potential new applications in biomedical industry. Increased usage of these NPs enhances the chance of exposure of personnel involved in the work place.

Objective: This study was designed to assess the ability of NiO NPs to cause biochemical alterations post-acute oral exposure in female Wistar rats.

Materials and methods: Rats were administered with 125, 250, and 500?mg/kg doses of NiO NPs for haematological, biochemical, and histopathological studies. Biodistribution patterns of NiO NPs in female Wistar rats were also monitored.

Results: NiO NPs caused significant (p?Conclusions: This study revealed that exposure to nanosized NiO particles at acute doses may cause adverse changes in animal biochemical profiles. Further, the in vivo studies on toxicity evaluation help in biomonitoring of the potential contaminants.     

Optimal sampling design to survey riparian bird populations with low detection probability

ABSTRACT

Capsule: Linear censusing and occupancy models based on fixed sampling points are alternative widely used techniques to determine bird densities in riparian ecosystems, although it cannot be always properly executed.

Aims: The aim is to assess the survey efficiency for river birds using occupancy models in contexts of impaired visibility owing to dense vegetation along the banks.

Methods: We tested whether increasing sampling periods within each survey unit (point) at occupancy models would result in increasing detection probability values. We used two approaches in order to identify the ‘best’ design for White-throated Dippers Cinclus cinclus along forested river stretches: minimizing survey effort of standard single-season site occupancy modelling and exploratory power analysis.

Results: With a detection probability of 0.26 (i.e. much lower than in previous studies), a design with 60 sites surveyed 10 min 6 times a year would be the option to survey White-throated Dippers in forested habitats if an acceptable power is required. Simulations further revealed the consistency of the results.

Conclusion: We provide guidelines to establish a cost-effective survey design for any long-term monitoring citizen-based programme of a White-throated Dipper population when detection probabilities are low. A strength and novelty of the method is to take advantage of advanced probabilistic approaches (e.g. GRTS) to select the survey sites providing, among other major interests, a spatially balanced geographic coverage.     

Development of a competitive immunoassay for the determination of N-(2-hydroxypropyl)valine adducts in human haemoglobin and its application in biological monitoring

Abstract

Propylene oxide (PO) is an important industrial compound and a directly acting mutagen. Human exposure to PO can be monitored by the determination of haemoglobin adducts. An immunoassay that quantifies the N-terminal adduct N-(2-hydroxypropyl)valine in whole haemoglobin was developed and its potential usefulness as a tool for biologically monitoring occupational exposure was demonstrated. Analytical reliability was confirmed in a comparative study with GC-MS (range 3.7–992 nmol g^?1 haemoglobin (Hb), correlation coefficient 0.99, n=10). The assay has been configured as a competitive enzyme-linked immunosorbent assay to facilitate the rapid throughput of samples. The assay employs a whole blood matrix and has a working range of 2–250 pmol g^?1 Hb. It does not appear to be affected by structurally similar metabolites and has been used to determine adducts in human blood samples. The first results in potentially exposed workers indicate the assay's high potential usefulness in routine occupational biomonitoring of exposure to PO.     

Immunological and cytotoxicological responses of the Asian clam,Corbicula fluminea (M.), experimentally exposed to cadmium

Abstract

Bivalve molluscs, as filter-feeding organisms, are known to accumulate metals that can produce deleterious effects on organisms. The phagocytic activity of haemocytes and lysosomal alterations in the digestive gland cells were measured in the freshwater Asian clam exposed to cadmium, in order to assess the possible use of immunocompetence and lysosomal responses as biomarkers of freshwater quality. Clams were exposed in the laboratory to nominal concentrations of 3, 10, 21.4, 46.5 and 100 µg l^?1 of cadmium and sampled after 7, 15 and 30 days of exposure. The results show a decrease of phagocytic activity after only 7 days of exposure to 10 µg l^?1 of cadmium. This response was also observed as the exposure time was increased. Lysosomes in the digestive cells increased in size and number after 7 days of exposure as cadmium concentration increased. After 30 days of exposure, a decrease in size and number indicated a change in the response to the metal from concentrations of 46.5 µg l^?1 of cadmium. A dose and time response both in phagocytic activity of haemocytes and lysosomal structure demonstrated a possible use of these biomarkers in freshwater biomonitoring.     

Assessment of DNA damages in lymphocytes of agricultural workers exposed to pesticides by comet assay in a cross-sectional study

Purpose: To assess the predictive power of the comet assay in the context of occupational exposure to pesticides.

Materials and methods: The recruited subjects completed a structured questionnaire and gave a blood sample. Exposure to pesticides was measured by means of an algorithm based on Dosemeci’s work (Agricultural Health Study). Approximately 50 images were analyzed for each sample via fluorescence microscopy. The extent of DNA damage was estimated by tail moment (TM) and is the product of tail DNA (%) and tail Length.

Results: Crude significant risks (odds ratios, ORs) for values higher than the 75th percentile of TM were observed among the exposed subjects (score?>?1). The frequency of some confounding factors (sex, age and smoking) was significantly higher among the exposed workers. A significant dose–effect relationship was observed between TM and exposure score. Significant high-risk estimates (ORs), adjusted by the studied confounding factors, among exposure to pesticides and TM, % tail DNA and tail length were confirmed using unconditional logistic regression models.

Conclusions: The adjusted associations (ORs) between the comet parameters and exposure to pesticides were significant. The sensitivity of the comet test was low (41%), the specificity (89%) and the predictive positive value (0.77) were found acceptable.     

Metal concentrations and metallothionein metal detoxification in blue sharks,Prionace glauca L. from the Western North Atlantic Ocean

BackgroundElasmobranchs are particularly vulnerable to environmental metal contamination, accumulating these contaminants at high rates and excreting them slowly. The blue shark Prionace glauca L. is one of the most heavily fished elasmobranchs, although information regarding metal contamination and detoxification in this species is notably lacking.MethodsBlue sharks were sampled in the western North Atlantic Ocean, in offshore waters adjacent to Cape Cod, Massachusetts. Total and metallothionein-bound liver and muscle metal concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS), metallothionein detoxification and oxidative stress endpoints were determined by UV–vis spectrophotometry.ResultsMetallothionein detoxification occurred for As, Cd, Cs, Cu, Hg, Pb, Se, Ti and Zn in liver, and for As, Cd, Cs, Pb, Se, and Zn in muscle, while reduced glutathione defenses seem to be related to Co and Zn exposure.ConclusionThis is the first report for several metals (Ag, Co, non-radioactive Cs, Sb, Ti and V) for this species, which will aid in establishing baseline elemental data for biomonitoring efforts, health metrics, and conservation measures.     

MGMT hypomethylation is associated with DNA damage in workers exposed to low-dose benzene

Objective: This study aims to assess the effects of low-dose benzene on DNA damage and O⁶-methylguanine-DNA methyltransferase (MGMT) methylation in occupational workers.

Materials and methods: We recruited 96 nonsmoking male petrochemical industry workers exposed to low-dose benzene and 100 matched control workers. Urinary S-phenylmercapturic acid (SPMA) and S-benzylmercapturic acid (SBMA) were measured for indicating internal exposure of benzene and toluene. The degree of DNA damage was determined by the Comet assay. The levels of MGMT methylation were detected quantitatively by bisulphite-PCR pyrosequencing assay.

Results: The benzene-exposed workers had significantly higher levels of urinary SPMA, degree of DNA damage but decreased MGMT methylation than the controls (all p?<?0.05). In contrast, the level of urinary SBMA does not differ between benzene-exposed workers and the controls. In all participants, MGMT methylation was negatively associated with the urinary SPMA and the degree of DNA damage, indicating that epigenetic regulation might be involved in response to low-dose benzene exposure-induced genetic damage.

Discussion and conclusion: MGMT methylation could be a potent biomarker associated with low-dose benzene exposure and benzene-induced DNA damage.     

Micronuclei as a marker for medical screening of subjects continuously occupationally exposed to low doses of ionizing radiation

Context: Genotoxicity assays are widely employed in human biomonitoring studies to assess genetic damage inflicted by genotoxic agents.

Objective: Evaluation of micronuclei (MN) as a screening marker of occupational ionizing radiation (IR) exposure.

Materials and methods: Using micronucleus test, peripheral blood lymphocytes (PBL) of 402 control and exposed subjects were screened for genetic damage.

Results: The mean frequencies of micronucleus test parameters were significantly higher in exposed persons. Increase of micronucleus yield with duration of exposure (DOE) by 0.303MN/year was revealed.

Discussion and conclusion: The obtained data encourage us to consider MN as valuable markers for preventive medical screening of occupationally exposed groups.     

Pneumoproteins and markers of inflammation and platelet activation in the blood of grain dust exposed workers

Abstract

Purpose: To investigate if blood biomarkers could indicate early signs of lung damage or cardiovascular risk due to exposure to grain dust.

Materials and methods: Pneumoproteins and markers of inflammation and platelet activation were analysed in blood samples of 102 grain elevator and compound feed mill workers. Differences between exposed (n?=?67) and controls (n?=?35), and associations with exposure measurements and respiratory health were investigated by multiple linear regression analyses.

Results: Concentrations of CC-16 and IL-6 were higher in exposed workers compared with controls (p?<?0.001 for both), whereas fibrinogen was lower (p?=?0.005). Concentrations of CRP, TNF-α, sCD40L and sP-selectin were similar in both groups. Serum CC-16 was significantly higher in workers with farm childhood, regardless of exposure. The impact of farm childhood on CC-16 interacted with smoking. None of the biomarkers were associated with exposure measurements or any of the tested respiratory health parameters.

Conclusion: Dust exposure induced inflammatory and anti-inflammatory reactions, but did not induce systemic inflammation and had no effect on platelet activation. No cause–effect relationship could be established in spite of relatively high exposure levels, particularly to endotoxin. Whether increased serum CC-16 is an early sign of lung damage or a reversible defense reaction remains unclear.     

Urinary and air biomonitoring of occupational exposure to benzene in oil pit workers

Abstract

The purpose of this study is to evaluate the personal exposure to benzene and its relationship with biomonitoring and quantitative risk assessment among the personnel working and living near oil pits. This study was conducted in one of oil subsidiary companies in Kharg in 2017. Airborne benzene exposure was evaluated over 8-h periods during work-shift by using personal active samplers. Urinary O-Cresol levels were determined using GC-FID for separation and detection. The highest mean concentration of airborne benzene was at monitoring location, A (0.53?ppm), monitoring location H (0.59?ppm) in the spring, monitoring location M (0.72?ppm) and monitoring location P (0.8?ppm) in the summer, which was more than suggested by the American Conference of Governmental Industrial Hygienists. No direct linear relationship was found between the concentration of airborne benzene, age, work experience, urinary creatinine, and O-Cresol in this study (p?>?.05). No significant difference was observed between urinary O-Cresol and benzene in occupational groups and different seasons (p?>?.05). The highest mean quantitative risk of cancers was observed in summer (1.21?±?0.47). According to the results of this study, urinary biomarker O-Cresol is not a suitable measure for evaluating exposure to environmental benzene.     

Book Reviews

Psychobiology: The Biological Bases of Behavior Pp. 382, illustrated. New York: Scientific American, 1967. 70s. (cloth), 40s. (paper). Reviewed by O. Lowenstein

Organisation in Plants W. M. M. BARON Pp. vi+218, 117 figs. London: Edward Arnold Ltd., 2nd ed., 1967.18s. (paper), 30s. (boards). Reviewed by J. W. Hannay

A First Biology ERIC SPRINGTHORPE Pp. 103. London: Longmans, Green & Co. Ltd., 1967. 10s. 6d. Reviewed by J. A. Barker

The Biology of Lichens MASON E. HALE, JR. Pp. viii + 176, 60 figs, 15 plates. London: Edward Arnold Ltd., 1967. 42s. Reviewed by K. A. Kershaw

Experiments in the Study of Biology J. J. W. BAKER, G. E. ALLEN, E. GAGE and S. K. WEBSTER Pp. 58. London: Addison-Wesley, 1967. Reviewed by C. F. Stoneman

Microbiological Methods C. H. COLLINS Pp. xii+404, illustrated. London: Butterworths, 2nd ed. 1967. 62s. Reviewed by N. J. Butler

The New Microbiology Ed. JOHN E. FLYNN New York: McGraw Hill Book Co., 1966. Reviewed by W. Howard Hughes

,i>Pergamon Programmed Texts Introduction to Genetics: Science of Heredity A. J. S. MCMILLAN Pp. 410, 64 figs, 6 plates. 1966. J. Audrey Stretch

An Introduction to Biochemistry Vol. 1 A. J. S. MCMILLAN Pp. 208. 1966. J. Audrey Stretch

Biology, Vol. 1 A. VERRINDER Pp. 274, 126 figs. 1966. Oxford: Pergamon Press. Commonwealth and International Library. 25s. (flexi-cover), 35s. (hard cover). J. Audrey Stretch

Grasses JAMES GROVES Published by the School Natural History Society, 1966, and obtainable from M. J. Wootton, Esq., 19A King's Gardens, Cranham, Upminster, Essex. 3s.

Biology Teaching in Schools Involving Experiment or Demonstration with Animals or with Pupils Compiled by J. J. BRYANT The Association for Science Education, 1967. 2s. 9d.

Handbook of Marine Biology for Borth, Cardiganshire A compilation of results and work completed by members of King Edward's School, Birmingham. Obtainable from the School. 6s. 6d.

Clarendon Biographies (16) Charles Darwin R. C. OLBY Pp. 64, 3 figs, 12 plates. London; Oxford University Press, 1967. 9s. 6d. (boards), 5s. (limp).

New Questions in O-Level Biology (Book 2) Plants and Invertebrates J. J. HEAD Pp. 70, illustrated. London: Oliver & Boyd, 1967. 6s. (Teachers' guide. Pp. 32. 5s.)

Revision Exercises in Biology J. D. MAUNDER and C. JOHNSTON Pp. xiii + 130, illustrated. Oxford: Pergamon Press, 1967. 8s. 6d.     

Observations on tolerance to heavy metals of four green algae in relation to pH

Abstract

The inhibition of growth by different concentration of eight heavy metals: Cd, Cr, Co, Cu, Hg, Ni, Se and Tl, in inorganic medium at pH 3 and 6.5, was studied in four green algae: Chlorella protothecoides Krüger, Chlorella saccharophila (Krüger) Migula, Coenochloris sp. and Stichococcus bacillaris Naegeli.

The results suggest that pH has an important effect on heavy metal toxicity in algae although it is difficult to establish a relationship between pH and heavy metals.     

Weather Forecasting: The View from Space…

Findley, James S.; Harris, Arthur H.; Wilson, Don E.; and Jones, Clyde Mammals of New Mexico Albuquerque: The University of New Mexico Press, 1975 360 pp., $8.50 Reviewed by Vagn Flyger

Piers, Helen Grasshopper and Butterfly New York: McGraw-Hill Book Co., 1975 80 pp., $5.95, library edition $5.72 Reviewed by N. N. Raghuvir

Gergely, Tibor Animals: A Picture Book of Facts and Figures New York: McGraw-Hill Book Co., 1975 47 pp., $5.95, library edition $5.72 Reviewed by Theodore W. Munch

Johnsgard, Paul A. Waterfowl of North America Bloomington, Indiana University Press 1975,575 pp. Reviewed by Kate Curry Vahle

Jacobson, Daniel The Fishermen (Indians of North America) New York: Franklin Watts, Inc., 1975 87 pp., $4.90 Reviewed by Robert W. Boenig

Janzen, Daniel H. Ecology of Plants in the Tropics (The Institute of Biology's Studies in Biology, No. 58) London: Edward Arnold (Distributed by Crane, Russak &; Co., New York), 1975 65 pp., $3.75 Reviewed by Rex E. Kerstetter

London, Carolyn The Hospital Doctors, Nurses and Mystery Workers New York: McGraw-Hill Book Co., 1976 86 pp., $5.72 Library Edition Reviewed by Philip C. Anderson

Buxton, Ralph Nature's Gliders Chicago: Children's Press, 1975 32 pp., individuals $6.60, institutions $4.95 Reviewed by Sue Hall

Clarke, H. T. (revised by B. Haynes) A Handbook of Organic Analysis: Qualitative and Quantitative (fifth edition) New York: Crane, Russak &; Co., 1975 291 pp., cloth $35.00, paper $16.00 Reviewed by Lawrence Powell Eblin

Simon, Seymour Discovering What Garter Snakes Do New York: McGraw-Hill Junior Books, 1975 48 pp., $4.72 Reviewed by Carl Gans

Dobbs, Austen, ed. The Birds of Nottinghamshire: Past and Present North Pomfret, Vt.: David &; Charles, 1975 226 pp., $17.00 Reviewed by Gerald R. Rising

Ashworth, J. M., and Dee, Jennifer The Biology of Slime Moulds (The Institute of Biology's Studies in Biology, No. 56) New York: Crane, Russak &; Co., Inc., 1975 67 pp., $3.75 Reviewed by Emanuel D. Rudolph

Exline, Joseph D. Individualized Techniques for Teaching Earth Science West Nyack, N.Y.: Parker Publishing Co., 1975 230 pp., $10.95 Reviewed by Waring B. Hill

Stadtfeld, Curtis K. Whitetail Deer: A Year's Cycle New York: The Dial Press, 1975 163 pp., $7.95 Reviewed by Paul F. Connor

Carrier, Rick Fly: The Complete Book of Sky Sailing New York: McGraw-Hill Book Co., 1975 128 pp., $7.95 Reviewed by A.D. Goddard

Duncan, Wilbur H. Woody Vines of the Southeastern United States Athens: The University of Georgia Press, 1975 76 pp., $2.50 Reviewed by A. J. Sharp

Barnes, R. S. K. Estuarine Biology (The Institute of Biology's Studies in Biology no. 49) New York: Crane, Russak &; Co., 1975 76 pp., $3.25 Reviewed by Brother G. Nicholas

Bendick, Jeanne How Heredity Works: Why Living Things Are As They Are (Finding-out books) New York: Parent's Magazine Press, 1975 64 pp., $4.59 Reviewed by Donald J. Nash     

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 1. Study design and methodology

Abstract

A randomized, multi-center study was conducted to assess potential improvement in health status measures, as well as changes in biomarkers of tobacco exposure and biomarkers of biological effect, in current adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) evaluated over 24 weeks. Study design, conduct and methodology are presented here along with subjects’ disposition, characteristics, compliance and safety results. This design and methodology, evaluating generally healthy adult smokers over a relatively short duration, proved feasible. Findings from this randomized study provide generalized knowledge of the risk continuum among various tobacco products.

Trial registration: ClinicalTrials.gov identifier: NCT02061917.     

Hen Harrier Circus cyaneus population trends in relation to wind farms

Capsule: The data presented here demonstrate a considerable spatial overlap between wind farms and the breeding distribution of Hen Harriers in Ireland, but evidence for a negative impact of wind farms on their population is weak.

Aims: To assess the extent of the overlap between wind farms and breeding Hen Harriers and to investigate their potential impact on Hen Harrier population trends.

Methods: Data on Hen Harrier breeding distribution in 10?km?×?10?km survey squares from national surveys were used in conjunction with information on the location of wind farms to examine whether, and to what extent, changes in Hen Harrier distribution and abundance between 2000 and 2010 were related to wind energy development.

Results: Of the 69 survey squares holding Hen Harriers during the 2010 breeding season, 28% also overlapped with one or more wind farms. Data from 36 of the squares with breeding Hen Harriers during the 2000 survey revealed a marginally non-significant negative relationship between wind farm presence and change in the number of breeding pairs between 2000 and 2010.

Conclusions: A considerable overlap exists between Hen Harrier breeding distribution and the location of wind farms in Ireland, particularly in areas between 200 and 400?m above sea level. The presence of wind farms is negatively related to Hen Harrier population trends in squares surveyed in 2000 and 2010, but this relationship is not statistically significant, and may not be causal. This is the first study to assess the influence of wind energy development on Hen Harriers at such a large geographic and population scale.     

Comet assay for assessment of DNA damage in greenhouse workers exposed to pesticides

Purpose: The main goal of the present study was to determine DNA damage in pesticide-exposed greenhouse workers and pesticides non-exposed controls.

Materials and methods: The DNA damage was measured by alkaline comet assay method (pH?>?13) in 41 greenhouse workers and 45 non-exposed individuals as the control. Pesticide exposure was assessed by duration of working in the greenhouse and pesticide application in the greenhouse time. DNA damage was estimated by arbitrary unit and damage frequency.

Results: Arbitrary unit and damage frequency were consistently significantly higher in greenhouse workers than those of the controls (p?=?0.001). In terms of gender in greenhouse, DNA damage of female workers was significantly higher than those in male workers (p?<?0.05). We found significant correlation between DNA damage and working hours spent. Multiple linear regression analysis showed that working hours in the greenhouse as an indication of pesticide exposure were significantly associated with the DNA damage, which can be attributed to the genotoxic potential of the pesticide mixture.

Conclusions: The comet assay is sensitive to detect the damage exposed to chronic effect of pesticides in greenhouse workers. Significant DNA damage was obtained for the exposed group, which was associated with the pesticide exposure.     

Methylene bis (2-chloroaniline) (MbOCA): towards a biological monitoring guidance value

Abstract

We report the development and validation of a high performance liquid chromatography method for the determination of methylene bis (2-chloroaniline) (MbOCA) and its labile conjugates in urine. The method has been in regular use for the biological monitoring of workers exposed to MbOCA for the past 11 years. Following the development of a biological monitoring strategy, and the introduction of a biological action level by the Health and Safety Commission in 1984, there has been a steady fall in the proportion of workers whose urinary results are above the action level. We conclude that, in the absence of reliable health-based data, a guidance value based on the use of the 90th percentile derived from monitoring a cross-section of the industry, can be used to interpret biological monitoring results. The measurement of urinary MbOCA is a practical non-invasive way of monitoring workers which can be useful in helping to control exposure.