Biological Monitoring (biological + monitoring)

Distribution by Scientific Domains

Selected Abstracts

Restoring Life in Running Waters: Better Biological Monitoring

Margaret A. Palmer

Measuring the amount of statistical information in the EPT index

Patty L. Kitchin
Abstract Biological monitoring is the process of measuring the effect of environmental stress on the environment. Aquatic macroinvertebrates are widely used in the monitoring of freshwater lotic systems. The macroinvertebrate fauna of a reference stream is commonly compared to the fauna of an impacted stream that is affected by an environmental stressor. The smaller the similarity between these two streams, the greater the effect of pollution or stress on the impacted stream. Many richness measures, or statistics, exist for measuring similarity. These statistics can be computed using different levels of taxonomic resolution (species, genus and family). Many aquatic biologists believe that species-level identifications, which require exorbitant time and expertise, are needed for correct data interpretations. The actual amount of information provided by these statistics at different taxonomic levels has never been measured. This article evaluates the amount of statistical information provided by the EPT index as compared to a sufficient statistic at the various levels of taxonomic resolution. Copyright 2004 John Wiley & Sons, Ltd. [source]

Urinary concentrations of bisphenol A in relation to biomarkers of sensitivity and effect and endocrine-related health effects

Mihi Yang
Abstract The impact of endocrine-disrupting chemicals (EDCs) on human health is not yet clear because of difficulties in ascertaining their biological effects. In the present study, we evaluated exposure to the EDC, bisphenol A (BPA), in 172 Koreans in relation to biomarkers of susceptibility and effect. The subjects completed questionnaires, which documented occupation, education, lifestyle factors, potential sources of BPA-exposure, and the occurrence of self-diagnosed endocrine disorders. None of the subjects were occupationallay exposed to BPA; however, urinary levels of conjugated BPA, determined by HPLC/FD, ranged from 0.03,62.4 ,g/l (median, 7.86). The frequencies of potential susceptibility biomarkers, the UGT1A6-Arg184Ser and the SULT1A1- Arg213His polymorphisms, were not associated with urinary BPA levels, either as single genes or in combination. Indirect effects of BPA exposure on the susceptibility to mutagens were evaluated by comparing urinary BPA concentrations with MNNG-induced sister-chromatid exchange (SCE) in lymphocytes cultured from the subjects. BPA exposure showed marginal or significant associations with theSCEs induced by the low doses of MNNG (0,0.4 mM). However, there was no overall association between urinary BPA levels and MNNG-induced frequency at doses ranging from 0.2,0.6 mM. Finally, we did not detect an association between urinary BPA concentration and endocrine-related disorders. Even though we were unable to find a strong association between BPA exposure and a biological response, possibly because of the limited number of subjects, we observed that most of the subjects were exposed to BPA. Therefore, continuous biological monitoring of BPA is a prudent measure to prevent possible BPA-related health risks. Environ. Mol. Mutagen., 2006. 2006 Wiley-Liss, Inc. [source]

Intraclonal variability in Daphnia acetylcholinesterase activity: The implications for its applicability as a biomarker

Liane Biehl Printes
Abstract The relationship between individual growth and acetylcholinesterase (AChE) activity was evaluated for Daphnia magna. Analysis on the influence of two different culture media on baseline AChE activity was performed with Daphnia similis. The results indicated an inverse relationship between D. magna body length and AChE activity. An increase in total protein, which was not proportional to an increase in the rate of the substrate hydrolysis (, absorbance/min), seems to be the reason for this inverse size versus AChE activity relationship. Therefore, toxicants such as phenobarbital, which affect protein and size but not AChE activity directly, have an overall affect on AChE activity. In contrast, the AChE inhibitor parathion altered AChE activity but not protein. Culture medium also had a significant affect on AChE activity in D. similis. Changes in total protein seem to be the main reason for the variations in baseline AChE activity in Daphnia observed in the different evaluations performed in this work. Therefore, AChE activity in Daphnia must be interpreted carefully, and variations related to changes in total protein must be taken into account when applying this enzyme as a biomarker in biological monitoring. [source]

The effect of fixed-count subsampling on macroinvertebrate biomonitoring in small streams

Craig P. Doberstein
Summary 1When rigorous standards of collecting and analysing data are maintained, biological monitoring adds valuable information to water resource assessments. Decisions, from study design and field methods to laboratory procedures and data analysis, affect assessment quality. Subsampling - a laboratory procedure in which researchers count and identify a random subset of field samples - is widespread yet controversial. What are the consequences of subsampling? 2To explore this question, random subsamples were computer generated for subsample sizes ranging from 100 to 1000 individuals as compared with the results of counting whole samples. The study was done on benthic invertebrate samples collected from five Puget Sound lowland streams near Seattle, WA, USA. For each replicate subsample, values for 10 biological attributes (e.g. total number of taxa) and for the 10-metric benthic index of biological integrity (B-IBI) were computed. 3Variance of each metric and B-IBI for each subsample size was compared with variance associated with fully counted samples generated using the bootstrap algorithm. From the measures of variance, we computed the maximum number of distinguishable classes of stream condition as a function of sample size for each metric and for B-IBI. 4Subsampling significantly decreased the maximum number of distinguishable stream classes for B-IBI, from 8.2 for fully counted samples to 2.8 classes for 100-organism subsamples. For subsamples containing 100,300 individuals, discriminatory power was low enough to mislead water resource decision makers. [source]

Neurotoxic effect of occupational exposure to mixed organic solvents in Korea: Posturographic study

Jae-Beom Park MD
Abstract Background This study used static posturography to investigate the neurotoxic effects on workers exposed to mixed organic solvents at low concentrations under the levels of the threshold limit values (TLV). Methods Forty-one workers from four plants exposed to mixed solvents and 90 non-exposed referents were examined. The lifetime cumulative biological exposure (CE) was estimated according to subject's occupational history and biological monitoring results. Static posturography and questionnaire were the basis of data collection. Results The mean exposure index of mixed organic solvents of four plants was 0.47 (SD: 0.33, range: 0.08,1.39). The exposed group showed a larger sway area and length under the eye open condition than did the non-exposed group. In a multiple linear regression, a significant positive association was demonstrated between postural sway area and CE. Conclusions This study results suggest that the exposure to organic solvents under TLV levels may cause disturbance in postural stability. Am. J. Ind. Med. 52:429,437, 2009. 2009 Wiley-Liss, Inc. [source]

Evaluating measurement error in estimates of worker exposure assessed in parallel by personal and biological monitoring

Elaine Symanski PhD
Abstract Background While studies indicate that the attenuating effects of imperfectly measured exposure can be substantial, they have not had the requisite data to compare methods of assessing exposure for the same individuals monitored over common time periods. Methods We examined measurement error in multiple exposure measures collected in parallel on 32 groups of workers. Random-effects models were applied under both compound symmetric and exponential correlation structures. Estimates of the within- and between-worker variances were used to contrast the attenuation bias in an exposure-response relationship that would be expected using an individual-based exposure assessment for different exposure measures on the basis of the intra-class correlation coefficient (ICC). Results ICC estimates ranged widely, indicative of a great deal of measurement error in some exposure measures while others contained very little. There was generally less attenuation in the biomarker data as compared to measurements obtained by personal sampling and, among biomarkers, for those with longer half-lives. The interval ICC estimates were oftentimes wide, suggesting a fair amount of imprecision in the point estimates. Ignoring serial correlation tended to over estimate the ICC values. Conclusions Although personal sampling results were typically characterized by more intra-individual variability than inter-individual variability when compared to biological measurements, both types of data provided examples of exposure measures fraught with error. Our results also indicated substantial imprecision in the estimates of exposure measurement error, suggesting that greater emphasis needs to be given to studies that collect sufficient data to better characterize the attenuating effects of an error-prone exposure measure. Am. J. Ind. Med. 50:112,121, 2007. 2006 Wiley-Liss, Inc. [source]

Plasma-lead concentration: Investigations into its usefulness for biological monitoring of occupational lead exposure

Ingvar A. Bergdahl
Abstract Background The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. Methods Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. Results Blood hemoglobin decreased with rising plasma lead (0.9,3.0 g/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. Conclusions Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects. Am. J. Ind. Med. 49:93,101, 2006. 2006 Wiley-Liss, Inc. [source]

Occupational risk in health care and research,

Daniela Vecchio MS
Abstract Background Working in the health care and research sectors has been linked to various hazards. Methods Studies published in the peer-reviewed literature that are pertinent to the exposures or diseases relevant to these fields were reviewed. Results The most important exposures include infectious agents, formaldehyde, anesthetic agents, antineoplastic drugs, and ethylene oxide. The best-documented evidence is that of infectious risk primarily among clinical personnel. Monitoring studies of persons occupationally exposed to anesthetics clearly demonstrate behavioral effects, possible risk of reproductive problems, as well as cytogenetic effects of unknown significance. The latter two impairments are also observed among those exposed to antineoplastic drugs and ethylene oxide. Exposure to formaldehyde appears to be associated with nasopharyngeal tumors. Whereas increased risk of cancer of certain sites, particularly the brain and lymphohematopoietic system, is found among research and health care personnel, no specific exposure has been linked to these neoplasms. Conclusions Although some results are inconsistent, continued environmental and biological monitoring will allow better assessment of exposures and of implemented protection measures. Am. J. Ind. Med. 43:369,397, 2003. 2003 Wiley-Liss, Inc. [source]

Determination of dichloroanilines in human urine by gas chromatography/mass spectrometry: validation protocol and establishment of Reference Values in a population group living in central Italy

Roberta Turci
3,4- and 3,5-Dichloroanilines (DCAs) are common markers of some non-persistent pesticides, e.g. linuron, diuron, vinclozolin, and iprodione. The general population may be exposed to these DCAs and/or their precursors mainly through diet. Since adverse effects on human health, such as endocrine disruption, have been reported, biological monitoring is essential for exposure assessment both of occupationally exposed subjects and of the general population. A highly sensitive and selective gas chromatography/mass spectrometry (GC/MS) method has been developed for the determination of 3,4- and 3,5-DCAs in urine using 4-chloro-2-methylaniline as an internal standard. The selected ion monitoring (SIM) mode was employed for quantitation of the analytes. The sample treatment procedure is simple and fast and no derivatization is required. The overall method was validated including uncertainty measurement. The limit of detection (LOD) and the lower limit of quantitation (LLOQ) were determined to be 0.005 and 0.010,g/L for both analytes. The method was then applied to the establishment of reference values for a population group living in a rural area of central Italy (Novafeltria, Marche). A total of 151 out of 153 samples were found to be positive for 3,5-DCA, and 81.7% were positive for 3,4-DCA. For this group, 3,4-DCA levels ranged from 0.01 to 6.19,g/L, while 3,5-DCA urinary concentrations were between 0.02 and 6.71,g/L. Copyright 2006 John Wiley & Sons, Ltd. [source]

A novel approach for identification and measurement of hemoglobin adducts with 1,2,3,4-diepoxybutane by liquid chromatography/electrospray ionisation mass spectrometry and matrix-assisted laser desorption/ionisation tandem mass spectrometry

Adriana Basile
The structural characterisation of the adducts formed by in vitro interaction of hemoglobin (Hb) with 1,2,3,4-diepoxybutane (DEB), the most reactive 1,3-butadiene (BD) metabolite, was obtained by liquid chromatography/electrospray ionisation mass spectrometry (LC/ES-MS) analysis of modified tryptic peptides of human hemoglobin chains. The reactive sites of human hemoglobin towards DEB and its hydroxylated derivatives (trihydroxybutyl (THB)-derivatives) were identified through the characterisation of alkylated tryptic peptides by matrix-assisted laser desorption/ionisation tandem mass spectrometry (MALDI-MS/MS). Based on this characterisation, a procedure was set up to measure the Hb-adducts of THB-derivatives by isotope dilution mass spectrometry with the use of a deuterated peptide standard. The results obtained here could permit optimisation of molecular dosimetry of BD-adducts, and extension of the analysis to the biological monitoring of occupational exposure to butadiene. Copyright 2001 John Wiley & Sons, Ltd. [source]

Determination of dimethyl sulfoxide and dimethyl sulfone in urine by gas chromatography,mass spectrometry after preparation using 2,2-dimethoxypropane

Akito Takeuchi
Abstract A method for routinely determination of dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO2) in human urine was developed using gas chromatography,mass spectrometry. The urine sample was treated with 2,2-dimethoxypropane (DMP) and hydrochloric acid for efficient removal of water, which causes degradation of the vacuum level in mass spectrometer and shortens the life-time of the column. Experimental DMP reaction parameters, such as hydrochloric acid concentration, DMP,urine ratio, reaction temperature and reaction time, were optimized for urine. Hexadeuterated DMSO was used as an internal standard. The recoveries of DMSO and DMSO2 from urine were 97,104 and 98,116%, respectively. The calibration curves showed linearity in the range of 0.15,54.45,mg/L for DMSO and 0.19,50.10,mg/L for DMSO2. The limits of detection of DMSO and DMSO2 were 0.04 and 0.06,mg/L, respectively. The relative standard deviations of intra-day and inter-day were 0.2,3.4% for DMSO and 0.4,2.4% for DMSO2. The proposed method may be useful for the biological monitoring of workers exposed to DMSO in their occupational environment. Copyright 2009 John Wiley & Sons, Ltd. [source]