Differences In Contamination Levels Research Articles

Contaminants and levels of occurrence in washed and shredded poly(ethylene terephthalate) from curbside collection. II: Validation of extraction procedures, particle size sampling and crystallinity

Part I of this study showed that washed and dried, shredded poly(ethylene terephthalate) (PET) (flake) obtained from curbside collection when Soxhlet extracted contained 26 semivolatile contaminants below the US FDA threshold of 215 ppb and six above this level. This paper reports the validation of the Soxhlet extraction technique by comparison with total dissolution with trifluoroacetic acid (TFA). The work was carried out for two of the three particle size ranges obtained by grinding the PET flake (300–425 and 425–700 μm) and for the unground flake. Further validation was undertaken by comparison of contaminant levels determined by total dissolution with TFA and sonication with dichloromethane (DCM) using flake ground to the 0–300 μm size range. The levels of contaminants increased with decreasing particle size range, but X-ray diffraction measurements of degrees of crystallinity were similar for each PET particle size range, thus showing that the differences in contaminant levels were not due to variable percentages of the amorphous material from the tops and bottoms of shredded bottles, relative to the amounts of crystalline PET from the mid-sections of the bottles. Hence, it was postulated that the variations in contaminant levels were due to selective grinding of the more highly contaminated surfaces, whilst the larger particles incorporated the less contaminated interior material. The grinding was also strongly selective with respect to the amorphous flake. Analysis of the segregated amorphous and crystalline flake phases indicated that many contaminants were similarly absorbed into both phases, whilst some were preferred by the amorphous PET and others were preferred by the crystalline PET.

Metal Levels in Fish from the Savannah River: Potential Hazards to Fish and Other Receptors

Fish are ideal indicators of heavy metal contamination in aquatic systems because they occupy different trophic levels and are different sizes and ages. In this paper, we report concentrations of arsenic, cadmium, chromium, copper, lead, manganese, strontium88 and mercury in the muscle of 11 species of fish from the Savannah River near the Savannah River Site. We test the hypotheses that there are no locational, species, or trophic-level differences in contaminant levels. There were significant species differences for all metals; higher-trophic-level fish generally had higher levels of arsenic, chromium, and copper. There were relatively few locational differences, and where there were such differences, they were small. The relationships between body weight and contaminant levels were generally positive, except for strontium, where there was a negative correlation for bowfin (Amia cal va), bass (Micropterus salmoides), yellow perch (Perca flavescens), and shellcracker (Lepomis microlophus) and no relationship for the other species. The levels of most metals were similar to, or lower than, those for the United States generally, and the levels of metals in fish from the Savannah River do not appear to pose a health threat to the fish themselves or to higher-order consumers, based on levels known to cause effects.

PCDDs, PCDFs, PCBs and DDE in edible marine species from the Adriatic Sea

Edible marine species from several areas of the Adriatic sea were analyzed for their content in persistent organic pollutants (POPs), such as polychlorinated dibenzodioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and pp ′-DDE (dichlorodiphenyldichloroethylene), a metabolite of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT). On the whole, PCDD/F contamination levels were low. In general, I-TEQ findings were greater for those species at higher levels in the trophic web (mackerel > red mullet > anchovy). Contamination levels were within 0.23 and 1.07 pg TEQ/g fw (fresh weight) in the aforesaid species, while all remaining species exhibited contamination levels ranging from approximately 0.07 to 0.25 pg TEQ/g fw. Besides, TEQ cumulative findings in species from the northern area were in general greater than those from the central and southern areas. PCB cumulative findings in the samples also revealed a detectable difference in contamination levels in species obtained from the northern, central, and southern sampling sites, between 7.6 and 177, 2.3 and 157, and 4.5 and 94 ng/g fw, respectively.The greatest PCB concentrations were found in mackerel (94–177 ng/g fw). Finally, DDE concentration levels varied from 0.7 to 32.4 ng/g fw. The highest levels of contamination were found in mackerel, red mullet and anchovy (17.7–32.4 ng/g fw, 8.1–9.8 ng/g fw, and 6.4–11.9 ng/g fw, respectively).

A Probability Model for Evaluating Building Contamination from an Environmental Event

ABSTRACT Asbestos dust and bioaerosol sampling data from suspected contaminated zones in buildings allowed development of an environmental data evaluation protocol based on the differences in frequency of detection of a target contaminant between zones of comparison. Under the assumption that the two test zones of comparison are similar, application of population proportion probability calculates the significance of observed differences in contaminant levels. This was used to determine whether levels of asbestos dust contamination detected after a fire were likely the result of smoke-borne contamination, or were caused by pre-existing/background conditions. Bioaerosol sampling from several sites was also used to develop the population proportion probability protocol. In this case, significant differences in indoor air contamination relative to the ambient conditions were identified that were consistent with the visual observations of contamination. Implicit in this type of probability analysis is a definition of “contamination” based on significant differences in contaminant levels relative to a control zone. Detection of a suspect contaminant can be assessed as to possible sources(s) as well as the contribution made by pre-existing (i.e., background) conditions, provided the test and control zones are subjected to the same sampling and analytical methods.

Evaluation of the Greenland AMAP programme 1994–1995, by use of power analysis (illustrated by selected heavy metals and POPs)

The levels of PCBs, HCB, HCHs, DDTs, Cd, Pb, Hg and Se, and especially the variability in biota obtained during Phase 1 of the Greenland AMAP-programme have been used to illustrate the ability of the programme to detect differences in contaminant levels over time. The statistical power of t-tests of contaminant levels are illustrated according to various scenarios of magnitude of change, significance level and sample size. The statistical power of various time series of contaminant levels to detect linear trends in mean log-concentrations, including a random between-year variation component, is illustrated. We conclude that the ability to detect differences is rather poor for many combinations of contaminants and media, and that long time series are needed before temporal trends are likely to be detected.

Assessment of various biomarkers in winter flounder from coastal Massachusetts, USA

AbstractSince 1992, the Massachusetts Water Resource Association has organized a Fish Day to assess the health of winter flounder in Boston Harbor and nearby areas. This report describes the levels of metal contaminants and selected biomarkers in flounder from Fish Day, 1996. Mean age for males and females was 3.5 years, which is lower than the age reported for fish collected during previous efforts. Body weight/body length ratios were significantly higher in females versus males. Liver Cd, As, Zn, and Cu, and muscle As were all elevated relative to U.S. Environmental Protection Agency designations for marine fish liver and muscle tissue in all animals from all sites. Male flounder from Boston Harbor had significantly higher liver Cd levels than female flounder from Cape Cod and Boston Harbor. Female flounder from Boston Harbor showed significantly less metallothionein (MT) protein and lower liver metal levels than those from Cape Cod. Metallothionein mRNA did not significantly differ between sites nor did MT protein or mRNA between males and females from Boston Harbor. Cytochrome P450 2E1 (CYP2E1)‐like and CYP1A1 activities were significantly higher at optimal temperatures than activity measured at field temperatures. No differences between groups were observed for either parameter at ambient temperatures, but at optimal temperature(s), Boston Harbor females had significantly higher CYP2E1‐like and CYP1A1 activities than Boston Harbor males. A negative correlation was found between maximal CYP1A1 activity and age for the Boston Harbor fish and a positive correlation for all fish between CYP2E1‐like activity at ambient temperature and percent liver lipid. No differences were observed for liver lipid and microsomal protein between any of the groups. Liver glycogen showed a sex‐dependent difference for the Boston Harbor group with levels in females significantly higher than males. These differences in contaminant levels and biomarkers are discussed within the context of data from previous Fish Days and the implications for flounder health within Boston Harbor.

Radiation contamination after the chernobyl nuclear accident and the effective dose received by the population of Croatia

Because of the Chernobyl nuclear accident which led to enhanced deposition of all fission products, contamination of the human environment in the Republic of Croatia was much higher than in the previous two decades. The paper deals with the investigation of deposition and contamination by fission product radionuclides ( 137Cs and 90Sr, in particular), especially within the human food chain. Its aim was to determine differences in contamination levels resulting from the Chernobyl accident and from large-scale atmospheric nuclear weapon tests. For the year following the Chernobyl accident, the radiation doses received from external and internal exposures were estimated for 1-year old infants, children at the age of 10-years and adults. The corresponding annual effective doses were 1·49, 0·93 and 0·83 mSv, respectively. The paper also gives data on the yearly intakes of 137Cs and 90Sr in foods and the corresponding effective doses received by the population of Croatia over many years from the global fallout following nuclear weapons testing and the Chernobyl accident.

Lymphoma Cell Burden in Progenitor Cell Grafts Measured by Competitive Polymerase Chain Reaction: Less Than One Log Difference Between Bone Marrow and Peripheral Blood Sources

A controversy persists in autologous transplantation as to which source of progenitor cells, bone marrow (BM) or peripheral blood (PB), contains the lowest number of contaminating lymphoma cells, and how mobilization procedures affect these numbers. To accurately measure the number of non-Hodgkin's lymphoma (NHL) cells harboring the bcl-2/immunoglobulin H (IgH) rearrangement in progenitor cell grafts, we developed a nested quantitative competitive polymerase chain reaction assay (QC-PCR). DNA from lymph nodes of four patients with NHL were cloned into the pSK(+) vectors to generate four internal controls (ICs) (two with major breakpoint region [MBR] and two with minor cluster region [mcr] rearrangements). The kinetics of amplification of ICs paralleled those of bcl-2/IgH rearranged genomic DNA. When used in a QC-PCR assay, these ICs were accurate at a 0.2-log level and provided reproducible results, as shown by low intrarun and interrun variability. An excellent correlation between predicted and observed lymphoma cell content (r = .99) was observed over a range of at least 5 logs of rearranged cells. This approach was used to measure involvement by NHL cells at the time of progenitor cell harvest in 37 autologous transplant patients. The number of bcl-2/IgH rearranged cells in BM, PB, and mobilized PB (mPB) was found to vary from 1 to 1.1 × 105 per million cells. The number of lymphoma cells present in BM was significantly higher than in PB (P = .0001), with a median difference in lymphoma cell content between BM and PB of 0.48 log of cells (range, −0.7 to 5 logs). In contrast, we found no difference in the concentration of bcl-2/IgH rearranged cells present in BM versus PB progenitor cells mobilized with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) (mPB) (P = .57). In conclusion, the QC-PCR assay described in this study could measure accurately and reproducibly the number of bcl-2/IgH rearranged cells among normal cells. Differences in levels of contamination by lymphoma cells between BM and PB were of less than one log (10-fold), and no differences in lymphoma cell concentrations were observed between BM and mobilized PB. As more cells are usually infused with mPB than with BM grafts, mPB progenitor cell grafts may actually be associated with higher levels of contamination by lymphoma cells. Furthermore, this QC-PCR assay should provide an important tool to assess the prognostic impact of lymphoma cell burden both in progenitor cell grafts and in vivo.

Lymphoma Cell Burden in Progenitor Cell Grafts Measured by Competitive Polymerase Chain Reaction: Less Than One Log Difference Between Bone Marrow and Peripheral Blood Sources

AbstractA controversy persists in autologous transplantation as to which source of progenitor cells, bone marrow (BM) or peripheral blood (PB), contains the lowest number of contaminating lymphoma cells, and how mobilization procedures affect these numbers. To accurately measure the number of non-Hodgkin's lymphoma (NHL) cells harboring the bcl-2/immunoglobulin H (IgH) rearrangement in progenitor cell grafts, we developed a nested quantitative competitive polymerase chain reaction assay (QC-PCR). DNA from lymph nodes of four patients with NHL were cloned into the pSK(+) vectors to generate four internal controls (ICs) (two with major breakpoint region [MBR] and two with minor cluster region [mcr] rearrangements). The kinetics of amplification of ICs paralleled those of bcl-2/IgH rearranged genomic DNA. When used in a QC-PCR assay, these ICs were accurate at a 0.2-log level and provided reproducible results, as shown by low intrarun and interrun variability. An excellent correlation between predicted and observed lymphoma cell content (r = .99) was observed over a range of at least 5 logs of rearranged cells. This approach was used to measure involvement by NHL cells at the time of progenitor cell harvest in 37 autologous transplant patients. The number of bcl-2/IgH rearranged cells in BM, PB, and mobilized PB (mPB) was found to vary from 1 to 1.1 × 105 per million cells. The number of lymphoma cells present in BM was significantly higher than in PB (P = .0001), with a median difference in lymphoma cell content between BM and PB of 0.48 log of cells (range, −0.7 to 5 logs). In contrast, we found no difference in the concentration of bcl-2/IgH rearranged cells present in BM versus PB progenitor cells mobilized with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) (mPB) (P = .57). In conclusion, the QC-PCR assay described in this study could measure accurately and reproducibly the number of bcl-2/IgH rearranged cells among normal cells. Differences in levels of contamination by lymphoma cells between BM and PB were of less than one log (10-fold), and no differences in lymphoma cell concentrations were observed between BM and mobilized PB. As more cells are usually infused with mPB than with BM grafts, mPB progenitor cell grafts may actually be associated with higher levels of contamination by lymphoma cells. Furthermore, this QC-PCR assay should provide an important tool to assess the prognostic impact of lymphoma cell burden both in progenitor cell grafts and in vivo.

The microbiological quality of street foods in Jakarta as compared to home-prepared foods and foods from tourist hotels

Street foods are ready-to-eat foods which are important for the diet of especially poor people in developing countries. However, street foods are often suspected of being contaminated with pathogenic bacteria. The quality of street foods was compared with similar home-prepared foods and foods obtained from tourist hotels. Samples of three types of Indonesian dishes were analyzed for indicator organisms using dry hydratable film. Additional western meals were also obtained from the hotels. Background information was obtained from the food preparers by using a questionnaire. The microbial quality of nasi goreng (fried rice) and sate ayam (grilled chicken with peanut sauce) was usually acceptable: numbers of total coliform were low and often no Escherichia coli was found. Gado gado (a dish mainly consisting of vegetables, peanut sauce and bean curd) had higher contamination levels. The gado gado obtained from street food vendors had especially high counts of total coliform and Escherichia coli with median counts of 5.5 × 106 (total coliform) and 6.0 × 103 (E. coli), respectively. The serving temperature might contribute to this difference in contamination level because nasi goreng and sate ayam are served hot and gado gado is served cold. The quality of the three western foods obtained from hotels was not better than that of the Indonesian dishes served; however the quality differed among the four hotels from which samples were obtained. Even food obtained from five-star hotels was sometimes unsafe (counts per gram for APC > 107; total coliform > 102; E. coli > 107). Lack of facilities and a limited knowledge of hygiene, particularly of the street food vendors, may have led to poor handling practices, such as storing cooked vegetables at ambient temperature for long periods, resulting in relatively high levels of contamination.

Differences Between Barley, Oats and Wheat in the Occurrence of Deoxynivalenol and Other Trichothecenes in Norwegian Grain

AbstractThe amount of the Fusarium toxins deoxynivalenol (DON). 3‐acety‐DON. ivalenol and fusarenon × have been determined in about 3000 samples of barley, oats and wheat grown in Norway. The samples were collected in the period 1988–1994. and grouped according to grain species, year of production, district and sample category. The DON content was found to be significantly higher in oats than both barley and wheat in grain produced by ordinary grain producers in Norway. Of samples collected from grain silos. 68.7% of the barley. 97.1% of the oats and 66.3% of the wheat samples were found to contain 30 mg/kg of DON or more. The proportion containing 1000 μg kg or more was 2.1.13.4and0.0% in burley, oats and wheat, respectively. However, these variations in contamination level were not reflected in the results from two field trials, where the grain species were grown side‐by‐side in the same fields. The differences in contamination level between the grain species seem to be due partly to edaphic and agrotechnical factors and partly to variation in the susceptibility to different Fusarium species in interaction with climatic factors. Nivalenol(≥ 50 μg/kg) was detected in 8.3% of the barley samples. 8.2% of the oats and 0.4% of the wheat samples. Samples collected at the grain silos were then not included.

Comparative study of contaminants in the mudpuppy (amphibia) and the common snapping turtle (reptilia), St. Lawrence River, Canada

Levels of organochlorine pesticides, polychlorinated biphenyl (PCB) congeners and mercury were measured in mudpuppy bodies, livers and gonads and in snapping turtle eggs to determine how the composition and concentration of these bioaccumulated contaminants differ between the two species. Furthermore, the geographic variation in contamination patterns were examined between the highly polluted St. Lawrence River and the much less polluted Ottawa River, Canada. Principal component analysis performed with 69 tissue samples (30 samples of mudpuppy tissues and 39 turtle egg clutches) indicated distinct contamination patterns in the two species for PCB congeners; PCB congener composition in mudpuppies resembled the pattern reported for fish while the turtle pattern was more akin to the bird pattern. This could be related to the metabolic capacity of each species. The organochlorine pesticide contamination profile was also species-specific although highly variable among locations. Contamination profiles were similar for mudpuppy gonads and carcasses but lipidweight basis concentrations were often a little higher in gonads. In both species, geographic variations in contamination patterns were noticeable and significant differences in contamination levels were detected between Ottawa River and St. Lawrence River samples. However, in both species, concentrations varied considerably within a single location. Sources of variability are discussed although the basic life history of these species in the St. Lawrence River system is relatively unknown.

Biological pathways of radionuclides originating from the Chernobyl fallout in a boreal forest ecosystem

In an attempt to understand the mechanisms governing the transfer and retention of radiocaesium in the understorey vegetation, 39 macromycetes species and 33 plant species, together with humus samples, were systematically collected from the undercover vegetation in a boreal coniferous forest. The results indicate that the main factors determining interspecific differences in contamination level are the rooting depth in plants, the depth of mycelium in fungi, and the ecophysiological behaviour of fungi, mycotrophism or plant parasitism. A comparison between the investigated species and the same species growing in similar ecosystems, albeit under different climatic conditions, resulted in an almost identical ranking in terms of radiocaesium contamination levels; the contamination ratios between species were also relatively constant. From an experiment involving humus samples, it was shown that up to 40% of the radiocaesium could be retained by the microflora, particularly by mycelia.

Fingerprints of some chlorinated hydrocarbons in plant foliage from Africa

Concentrations of DDTs, HCHs and HCB in foliage have been used to evaluate the contamination levels of two African areas and Seychelles and Mauritius Islands. Physico-chemical properties in combination with environmental features play the most important role in the global distribution of chlorinated hydrocarbons. However past and present applications appear to be significant in determining the characteristics of the contamination pattern in different areas. Results are discussed in comparison to previous African data. Remarkable differences in contamination levels are evident among the areas considered. Log-Probit and Correspondence Factor Analyses are used for the characterization of the typical distribution pattern of each area. Relative differences in the composition of the pollutant mixture (HCHs dominance, different DDE/DDT ratios etc.) seem to indicate a “fingerprint” of the contamination for each geographical-economical homogeneous region.

Habitat Partitioning and Contaminant Exposure in Cyprinids

Four species of forage fish from the Huron–Erie corridor — Labidesthes sicculus, a surface feeder; Notropis atherinoides, a facultative surface feeder; Notropis hudsonius, a facultative benthivore; and Pimephales notatus, a benthivore — were found to have significantly different levels of organochlorine contaminants with high 1-octanol/water partition coefficients (Kow). Chemical levels were greatest in P. notatus, reflecting its greater exposure to contaminated sediments. The interspecific differences observed indicate that habitat partitioning is a major factor regulating contaminant levels in these forage fish species. These interspecific differences in contaminant levels have important implications for fugacity models which would predict that these differences should not exist. Although chemical and physiological parameters may determine which contaminants have the potential to bioaccumulate, it is the regulation of exposure through ecological processes that will determine the degree to which that potential is realized.

Organic micropollutants in the Rio de Janeiro coastal region, Brazil

Sediment samples from two protected bays and a lagoon with different environmental characteristics in the Rio de Janeiro coastal area (Brazil) were analyzed for four groups of hydrophobic organic micropollutants: PAHs, PCBs (both of industrial origin), DDT derivatives and Drins (chlorinated pesticides). Differences in contamination levels of the three studied areas reflect the different land use in the vicinity of the examined bays and lagoon: the presence of cities, industries or agricultural activities. A comparison of the contamination of the Rio de Janeiro coastal area with the contamination in the North Sea (Europe) indicates lower levels for the industrial pollutants (PCBs, PAHs) in the Brazilian samples; chlorinated pesticide levels are comparable in both sampling areas.