Metal concentrations in chrionomids in relation to peatland geochemistry

Concentrations of Zn, Cu, Al, Fe, and Mn were determined in Chironomidae (Diptera) larvae sampled from three sites within eight peatlands, located in south-central Ontario, Canada. The eight peatlands displayed a range in pH and alkalinity and were classified abiotically (i.e., chemically, hydrologically) and biotically (i.e., dominant vegetation present) as mineral-poor, moderately poor, or as mineral-rich fen. Surface peats of mineral-poor fens were distinct from those of moderately poor and mineral-rich fens; mineral-poor fens contained higher concentrations of organic matter with low concentrations of easily reducible Mn vs. the moderately poor and mineral rich fens. A one-way nested ANOVA indicated that chironomid metal concentrations were peatland dependent (P<0.05). To determine if differences in chironomid metal concentrations among the peatlands could be related to peat geochemistry, an R² MAX procedure using peat geochemistry as the independent variable and chironomid metal concentrations as the dependent variable was applied. Peat geochemistry was defined as concentrations of peat organic matter, reducible Fe (Fe oxides), reducible Mn (Mn oxides) and easily reducible metal (where metal = Zn, Cu, Al, Mn and Fe), and reducible metal and organically bound metal. Chironomids from mineralrich peatlands, i.e., peatlands low in organic matter with high concentrations of reducible Mn and Fe or easily extractable metal contained greater concentrations of Zn, Mn, and Fe vs. chironomids sampled from mineral poor peatlands, i.e., peatlands with high concentrations of peat organic matter and low concentrations of reducible Mn or easily extractable metal. In contrast, Cu concentrations were greatest in larvae sampled from mineral-poor vs. mineral-rich peatlands. Aluminum larvae concentrations were independent of peat geochemistry. We suggest that bioavailability of metals such as Zn, Fe, and Mn will be greater to invertebrates inhabiting mineral rich vs. mineral poor fens, whereas greater chironomid Cu concentrations will be found in chironomids sampled from mineral poor fens. Differences in metal availability to invertebrates among peatland types has important implications when comparing the impact of contaminant transfer to higher trophic levels among different types of peatlands.     

Cadmium bioavailability to three estuarine animals in relation to geochemical fractions to sediments

The effects of sediment characteristics and geochemical fractions on the biological availability of cadmium to estuarine animals were studied. Grass shrimp (Palaemonetes pugio), blue mussels (Mytilus edulis) and a polychaete (Nereis virens) were exposed to Cd-treated sediment for 14 days. The test populations were evaluated for mortalities, oxygen consumption (exceptN. virens), and bioaccumulation of Cd. Sediment Cd was extracted sequentially to determine the exchangeable (EP), easily reducible (ERP), organic-sulfide (OSP), moderately reducible (MRP), and acid extractable (AEP) geochemical phases.The shrimp displayed significant respiration effects; the shrimp and mussels bioaccumulated Cd, particularly in the Cd-sand treatments. The polychaete did not bioaccumulate Cd. The OSP contained the greatest concentrations of Cd in all treatments. The Cd-sands were characterized by relatively higher levels of EP and ERP than for silts or clays. A statistical model was developed that describes the bioaccumulation of Cd as a function of EP and ERP geochemical fractions of sediment Cd forM. edulis.     

Distribution of polycyclic aromatic hydrocarbons in the surficial sediments of Casco Bay,Maine

Bulletin of Environmental Contamination and Toxicology -     

Cadmium blood concentrations in relation to nutrition

Cadmium is a toxic element ubiquitous in the environment, which damages biological systems in various ways. The major source of cadmium exposure is food. High cadmium content in the soil leads to high cadmium concentrations in certain plants such as grains (above all surface layers and germs), oil or non-oil seeds, fruit and vegetables. These food commodities are the crucial components of a vegetarian nutrition. Blood cadmium concentrations were measured in two non-smoking population groups: the vegetarian group (n = 80) and the non-vegetarian (control) group of general population on traditional mixed diet (n = 84). The significantly higher blood cadmium content (1.78 +/- 0.22 vs. 0.45 +/- 0.04 microg/l) was measured in vegetarian group. Healthy risk values > 5 microg/l were found in 6 vegetarians vs. no non-vegetarian. The highest cadmium concentration (3.15 +/- 0.77 microg/l) was measured in vegan subgroup (plant food only, n = 10) and that value decreased with increasing animal food consumption (1.75 +/- 0.36 microg/l, lactovegetarian and lactoovovegetarian subgroup/added dairy products and eggs, n = 41/, 1.34 +/- 0.21 microg/I, semivegetarian subgroup /as a previous subgroup and added white meat, n = 291). Risk vegetarians vs. non-risk vegetarians consume significantly higher amounts of whole grain products, grain sprouts and oil seeds. Blood cadmium content is directly influenced by age (r = 0.32, p < 0.001), by whole grain product intake (r = 0.66, p < 0.001) and by duration of vegetarianism (r = 0.5, p < 0.001). Oxidative stress plays a major role in chronic cadmium induced hepatic and renal toxicity as well as in other consequences of cadmium injuries. Vegetarians have significantly higher plasma concentrations of natural antioxidants. The sufficient antioxidative protection against cadmium induced free radical formation in vegetarians may inhibit the harmful effects of greater cadmium intake from plant food.     

Origin and distribution of polycyclic aromatic hydrocarbons in surficial sediments from the savannah river

Surface sediments collected from the Savannah River, located in the southeastern state of Georgia, USA, in June–July 1994 were analyzed for individual polycyclic aromatic hydrocarbons (PAHs). Three subdivisions of the river were identified for the study: upstream from, adjacent to, and downstream from the city of Savannah. There was high spatial variability in the total PAH (ΣPAH) concentrations that ranged from 29 to 5,375 ng/g with an average concentration of 1,216 ± 1,161 (SD). Of the three subdivisions, the highest ΣPAH concentrations were in the middle segment, which was adjacent to urban and industrial areas. To elucidate sources, molecular indices based on indices among phenanthrene versus anthracene and fluoranthene versus pyrene were used to determine pyrogenic and petrogenic sources, respectively. These indices have been used by other authors to differentiate sources. In most cases, PAHs in sediments nearest the city of Savannah were of high temperature and pyrogenic origin. These pyrogenic PAHs were highly associated with toxicity to benthic organisms. The two-ringed naphthalene and substituted naphthalenes, which are petroleum-related PAHs, were significantly higher in the lower section of the river relative to the subdivisions. This river segment receives inputs primarily from shipping and boating traffic. Perylene, which is indicative of nonanthropogenic terrestrial inputs of carbon, had the highest concentration among the individual PAHs measured. High perylene concentrations were found at stations located upstream and adjacent to forested terrain and where salinity level was low. To discriminate pattern differences and similarities of individual PAHs among samples, principal component analysis (PCA) was performed on the more hydrophobic and persistent nonalkylated PAHs. These differences and similarities were used to infer perylene origin. PCA was performed on 14 nonalkylated PAHs that was normalized to the sum of nonalkylated PAHs, using a correlation matrix. Generally, the PAHs were separated into group patterns according to chemical and physical properties associated with log K _OW, except perylene. Perylene, a five-ringed PAH, was distinctly separated from the other five-ringed PAHs. The sources for perylene are likely from biogenic, terrestrial precursors. The collected data show that pyrogenic PAHs were highly associated with biological effects on benthic organisms, based on bioassay results. Perylene, a nonanthropogenic PAH, was found throughout the river and constituted a large percentage of total PAHs in the upper river. Received: 20 November 2001/Accepted: 3 May 2002     

Heavy metal concentrations in sediments from the coast of Bahrain

The concentration of lead, zinc, cadmium, nickel, copper and vanadium in the sediments of nineteen coastal stations in Bahrain were determined by atomic absorption spectrophotometer (AAS). The results showed widespread occurrence of anomalously high levels of heavy metals owing to pollution, especially, zinc and lead, and the overall mean value in sediments for Pb, Zn, Cd, Ni, Cu and V of 111, 104, 1.17, 40.5, 15.1 and 21.9 mg/kg, respectively. In certain areas, the concentrations of some of these heavy metals, especially lead, were much higher. This could be the result of pollution from land-based industrial and urban sources, namely automobiles, which contribute to the overall pollution in the coastal areas. Refineries and other industries, as well as sewage effluents, discharge their liquid wastes in the shallow coastal areas and are sometimes untreated or partially treated. Heavy metal concentrations in areas located near industries were generally higher than in the other regions of the island. The trend that has been noted in this study suggests that this pollution, if left unchecked, could pose a threat to mankind and to marine life. This study represents a limited number of sampling stations in Bahrain. To assess metal pollution in Bahrain and within the Arabian Gulf, and to establish a more realistic baseline, it is suggested that a more detailed study of metal concentrations in the sediments from the coastal areas of Bahrain be conducted.     

Metal concentrations in human pancreatic juice

Concentrations of 11 metals (cadmium [Cd], lead [Pb], copper [Cu], iron [Fe], manganese [Mn], cobalt [Co], chromium [Cr], nickel [Ni], zinc [Zn], magnesium [Mg], and calcium [Ca]) and protein in human pancreatic juice were studied. Human pancreatic juice was sampled by endoscopic cannulation after administration of secretin (intravenous [i.v.], 1 mu/kg). There were 19 subjects (11 males and 8 females) and the means of their ages were 50.3 yr (male, 20-68 yr) and 52.5 yr (female, 45-64 yr). Diagnoses were: normal, 5; early pancreatic cancer, 9; and chronic pancreatitis, 5. None had symptoms suggestive of disturbances in endocrine and exocrine functions of the pancreas. Concentrations of metals and protein in pancreatic juice did not change significantly between males and females or with pathological changes in the pancreas. Assuming the flow rate of pancreatic juice to be 1500-2000 ml/day, the daily excretions of metals into duodenum via pancreatic juice were calculated as follows (mumoles of metal/day): Cd, 0.012-0.012; Pb, 0.216-0.288; Cu, 6.20-8.26; Fe, 2.34-3.12; Mn, 0.100-0.133; Co, 0.165-0.220; Zn, 7.46-9.94; Cr, 0.084-0.112; Mg, 274.1-365.4; Ni, 1.64-2.18; and Ca, 0.221-0.295. Toxic (Cd and Pb) and essential metals (Cu, Zn, Fe, Mn, Cr, and Ni) are excreted daily into duodenum via pancreatic juice.     

Plasma concentrations of the antioxidants beta-carotene and alpha-tocopherol in relation to lung function

OBJECTIVE: To study the association between plasma antioxidants (beta-carotene and alpha-tocopherol) and lung function in Dutch adults aged 20-59 y. DESIGN: Cross-sectional. SETTING: Population-based study. Subjects: A random sample (n=367) was drawn from all participants (men and women) aged 20-59 y with reproducible lung function measurements in 1995. INTERVENTION: Completion of general questionnaire and physical examination. MAIN OUTCOME MEASUREMENTS: Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and plasma levels of beta-carotene and alpha-tocopherol. RESULTS: Subjects with a high plasma beta-carotene level (90th percentile, that is 0.57 micromol/L) tended to have a higher FEV1 (73 ml, s.e.m. 60 ml; P=0.22) and a higher FVC (147 ml, s.e.m. 76 ml; P=0.05) than subjects with a low plasma beta-carotene level (10th percentile, that is 0.11 micromol/L) after adjustment for age, height, gender, smoking status, pack-years of smoking and alcohol consumption. There was no difference in lung function between subjects with high and low plasma alpha-tocopherol concentrations. CONCLUSIONS: The results suggest that subjects with a high plasma beta-carotene tended to have a higher FVC than subjects with a low plasma beta-carotene concentration which was borderline statistically significant. The difference for FEV1 between high and low levels of plasma beta-carotene tended to be in the same positive direction as that of FVC but did not reach the pre-set statistical significance level. There is no relation between plasma alpha-tocopherol and lung function. SPONSORSHIP: Ministry of Public Health, Welfare and Sports of the Netherlands and the National Institute of Public Health and the Environment.     

Serum concentrations of polychlorinated biphenyls in relation to in vitro fertilization outcomes

Background: Human exposure to polychlorinated biphenyls (PCBs) remains widespread. PCBs have been associated with adverse reproductive health outcomes including reduced fecundability and increased risk of pregnancy loss, although the human data remain largely inconclusive.Objective: Our goal was to explore the relationship between serum PCB concentrations and early pregnancy loss among a large cohort of women undergoing in vitro fertilization (IVF) between 1994 and 2003.Methods: Concentrations of 57 PCB congeners were measured in serum samples collected during 827 IVF/intracytoplasmic sperm injection cycles from 765 women. Joint statistical models that accommodate multiple outcomes and multiple cycles per woman were used to assess the relationship between serum PCB quartiles and implantation failure, chemical pregnancies (human chorionic gonadotropin level > 5.0 mIU/mL) that did not result in clinical pregnancy, or spontaneous abortion, while also adjusting for confounders.Results: PCB-153 was the congener present in the highest concentration (median, 46.2 ng/g lipid). Increasing quartiles of PCB-153 and the sum of all measured PCB congeners (ΣPCBs) were associated with significantly elevated dose-dependent odds of failed implantation. Adjusted odds ratios (95% confidence interval) for highest versus lowest quartile were 2.0 (1.2–3.4) for PCB-153 and 1.7 (1.0–2.9) for ΣPCBs. There were suggestive trends for increased odds of implantation failure for PCB-118 and cytochrome P450–inducing congeners (p-values for trend = 0.06). No statistically significant associations between PCBs and chemical pregnancy or spontaneous abortion were found.Conclusions: Serum PCB concentrations at levels similar to the U.S. general population were associated with failed implantation among women undergoing IVF. These findings may help explain previous reports of reduced fecundability among women exposed to PCBs.     

Effects of Tri-, Di- and monobutyltin on heterotrophic nitrifying bacteria from surficial estuarine sediments

Four heterotrophic nitrifying bacteria—two Bacillus spp., an unidentified gram-positive rod and a gram-negative rod tentatively identified as a Pseudomonas sp.—were isolated from surficial sediments from Boston Harbor, Massachusetts. None of the organisms produced a detectable level of NO ₃ ^– . Nanomolar levels of tributyltin (TBT) and its degradation products dibutyltin (DBT) and monobutyltin (MBT) were examined for their effects on growth, NH ₄ ⁺ - uptake and N-oxidation by the organisms. TBT inhibited growth of all four isolates. DBT inhibited growth of Bacillus sp. SC-2 and the unidentified gram-positive rod. Growth of the Pseudomonas sp. was inhibited by exposure to 100 nM MBT. NH ₄ ⁺ uptake was inhibited, even by butyltin species that did not inhibit growth. Free NH₂OH production and NO ₂ ^– production were inhibited by TBT but varied from being inhibited to being stimulated with different DBT or MBT exposure regimes. Nitrite production was affected differently from free NH₂OH production for Bacillus sp. SC-2 and the unidentified rod. DBT appears to be particularly toxic to NH₂OH oxidation by these four organisms. At the concentration used, TBT was more toxic than DBT or MBT. The results suggest that butyltins have the potential to affect nitrification by heterotrophic bacteria in the aquatic environment at nanomolar levels and that degradation of TBT to DBT and MBT does not necessary detoxify it.     

Blood pressure in relation to concentrations of PCB congeners and chlorinated pesticides

Background

Residents of Anniston, Alabama, live near a Monsanto plant that manufactured polychlorinated biphenyls (PCBs) from 1929 to 1971 and are relatively heavily exposed.

Objectives

The goal of this study was to determine the relationship, if any, between blood pressure and levels of total serum PCBs, several PCB groups with common actions or structure, 35 individual PCB congeners, and nine chlorinated pesticides.

Methods

Linear regression analysis was used to determine the relationships between blood pressure and serum levels of the various contaminants after adjustment for age, body mass index, sex, race, smoking, and exercise in 394 Anniston residents who were not taking antihypertensive medication.

Results

Other than age, total serum PCB concentration was the strongest determinant of blood pressure of the covariates studied. We found the strongest associations for those PCB congeners that had multiple ortho chlorines. We found the associations over the full range of blood pressure as well as in those subjects whose blood pressure was in the normal range. The chlorinated pesticides showed no consistent relationship to blood pressure.

Conclusions

In this cross-sectional study, serum concentrations of PCBs, especially those congeners with multiple ortho chlorines, were strongly associated with both systolic and diastolic blood pressure.     

Plasma carotenoid concentrations in relation to acute respiratory infections in elderly people

A high plasma carotenoid concentration could improve the immune response and result in decreased risk of infectious diseases. However, data on the relationship of plasma carotenoid concentration with acute respiratory infections, which occur frequently in elderly people, are scarce. We investigated, therefore, the relationship of plasma concentrations of six major carotenoids (beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin) with the incidence and severity of acute respiratory infections. Baseline data from an intervention trial were used. Participants were 652 non-institutionalized elderly people (> or =60 years old) enrolled via two community-based sampling strategies in the Wageningen area of The Netherlands in 1998-99. Plasma carotenoid concentrations were divided into quartiles, the lowest being the reference. Frequency and severity of episodes during the previous 1 year, i.e. staying in bed, medical consultation and episode-related medication, were self-reported by means of a questionnaire. On average 1.6 episodes per person were recorded. The incidence rate ratio of acute respiratory infections at high beta-carotene status was 0.71 (95 % CI 0.54-0.92) as compared with the low beta-carotene concentration group. No association was observed between beta-carotene and illness severity. alpha-Carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin were not related to incidence or severity of the infections. We conclude that elderly people with a high plasma beta-carotene concentration may have a lower occurrence of acute respiratory infections.     

Macular pigment density in relation to serum and adipose tissue concentrations of lutein and serum concentrations of zeaxanthin

BACKGROUND: Macular pigment (MP), concentrated in the central area of the retina, contains the carotenoids lutein and zeaxanthin. A low MP density could be a risk factor for age-related macular degeneration. Little information is available regarding MP density in relation to serum lutein and zeaxanthin and adipose lutein concentrations in a general population. OBJECTIVE: The objective was to investigate the associations between MP density and serum lutein, serum zeaxanthin, and adipose lutein, taking into account potential confounders in a population. DESIGN: Volunteers (n = 376) aged 18-75 y were recruited. In a cross-sectional design, serum (n = 376) and adipose tissue (n = 187) were analyzed for carotenoids, and MP density was measured by spectral fundus reflectance. RESULTS: Mean MP density in the total study group was 0.33 +/- 0.15. MP density was 13% higher in men than in women (P < 0.05). Serum and blood concentrations of alpha-tocopherol, vitamin C, and all carotenoids except lycopene were significantly higher in women. Adipose lutein concentrations were also significantly higher in women than in men. Regression models showed a positive significant association between MP density and serum lutein, serum zeaxanthin, and adipose lutein concentrations in men after adjustment for age, but no relation in women. In men, serum lutein remained significantly associated with MP density after adjustment for age, total cholesterol, body mass index, and smoking. CONCLUSION: The associations between MP density and serum lutein, serum zeaxanthin, and adipose lutein concentrations are stronger in men than in women.     

Heavy metals concentrations in the sediments from Kolleru Lake,India

Kolleru Lake is the largest natural freshwater lake of Andhra Pradesh in India. It is situated between the latitudes 16 degrees 32(1) and 16 degrees 47(1)N and longitude 81 degrees 05(1) and 81 degrees 21(1) E. The catchment area of the lake is 4763 sq. km. The sediment samples were collected at different points from Kolleru Lake in three seasons a year over a period of three years and analyzed for heavy metals and organic matter. Concentrations of Cu, Pd, Cd, Mn, Ni, Co, Fe and Zn in the sediments were analysed by using Atomic absorption spectrometer (AAS) and selected sediments samples were analysed for Be, Sr, Ba, B, Mo, Tl, V, Cr, Ag, Bi, As and Se by using inductively coupled plasma Mass Spectrometer (ICP-MS).