Adsorption Characterization of Lactobacillus sp. for Di-(2-ethylhexyl) phthalate.

Di-(2-ethylhexyl) phthalate (DEHP) is the widely detected plasticizer in foods whose exposure is associated with a myriad of human disorders. The present study focused on identifying Lactobacillus strains with high adsorption potential towards DEHP and further elucidating the mechanism of binding using HPLC, FTIR and SEM. Two strains, Lactobacillus rhamnosus GG and Lactobacillus plantarum MTCC 25,433, were found to rapidly adsorb more than 85% of DEHP in 2 h. Binding potential remained unaffected by heat treatment. Moreover, acid pre-treatment enhanced the DEHP adsorption. Chemical pre-treatments, such as NaIO4, pronase E or lipase, caused reduction in DEHP adsorption to 46% (LGG), 49% (MTCC 25,433) and 62% (MTCC 25,433), respectively, attributing it to cell wall polysaccharides, proteins and lipids. This was also corroborated by stretching vibrations of C = O, N-H, C-N and C-O functional groups. Furthermore, SDS and urea pre-treatment, demonstrated the crucial role of hydrophobic interactions in DEHP adsorption. The extracted peptidoglycan from LGG and MTCC 25,433 adsorbed 45% and 68% of DEHP, respectively, revealing the imperative role of peptidoglycan and its integrity in DEHP adsorption. These findings indicated that DEHP removal was based on physico-chemical adsorption and cell wall proteins, polysaccharides or peptidoglycan played a primary role in its adsorption. Owing to the high binding efficiency, L. rhamnosus GG and L. plantarum MTCC 25,433 were considered to be a potential detoxification strategy to mitigate the risk associated with the consumption of DEHP-contaminated foods.

Genetic associations of TMEM154, PRC1 and ZFAND6 loci with type 2 diabetes in an endogamous business community of North India.

BACKGROUND: More than 250 loci have been identified by genome-wide scans for type 2 diabetes in different populations. South Asians have a very different manifestation of the diseases and hence role of these loci need to be investigated among Indians with huge burden of cardio-metabolic disorders. Thus the present study aims to validate the recently identified GWAS loci in an endogamous caste population in North India. METHODS: 219 T2D cases and 184 controls were recruited from hospitals and genotyped for 15 GWAS loci of T2D. Regression models adjusted for covariates were run to examine the association for T2D and fasting glucose levels. RESULTS: We validated three variants for T2D namely, rs11634397 at ZFAND6 (OR = 3.05, 95%CI = 1.02-9.19, p = 0.047) and rs8042680 at PRC1 (OR = 3.67, 95%CI = 1.13-11.93, p = 0.031) showing higher risk and rs6813195 at TMEM154 (OR = 0.28, 95%CI = 0.09-0.90, p = 0.033) showing protective effect. The combined risk of 9 directionally consistent variants was also found to be significantly associated with T2D (OR = 1.91, 95%CI = 1.18-3.08, p = 0.008). One variant rs10842994 at KLHDC5 was validated for 9.15mg/dl decreased fasting glucose levels (SE = -17.25-1.05, p = 0.027). CONCLUSION: We confirm the role of ZFAND6, PRC1 and TMEM154 in the pathophysiology of type 2 diabetes among Indians. More efforts are needed with larger sample sizes to validate the diabetes GWAS loci in South Asian populations for wider applicability.

Genetic architecture of adiposity measures among Asians: Findings from GWAS.

Adiposity has gradually become a global public threat over the years with drastic increase in the attributable deaths and disability adjusted life years (DALYs). Given an increased metabolic risk among Asians as compared to Europeans for any given body mass index (BMI) and considering the differences in genetic architecture between them, the present review aims to summarize the findings from genome-wide scans for various adiposity indices and related anthropometric measures from Asian populations. The search for related studies, published till February 2022, were made on PubMed and GWAS Catalog using search strategy built with relevant keywords joined by Boolean operators. It was recorded that out of a total of 47 identified studies, maximum studies are from Korean population (n = 14), followed by Chinese (n = 7), and Japanese (n = 6). Nearly 200 loci have been identified for BMI, 660 for height, 16 for weight, 28 for circumferences (waist and hip), 32 for ratios (waist hip ratio [WHR] and thoracic hip ratio [THR]), 5 for body fat, 16 for obesity, and 28 for adiposity-related blood markers among Asians. It was observed that though, most of the loci were unique for each trait, there were 3 loci in common to BMI and WHR. Apart from validation of variants identified in European setting, there were many novel loci discovered in Asian populations. Notably, 125 novel loci form Asian studies have been reported for BMI, 47 for height, 5 for waist circumference, and 2 for adiponectin level to the existing knowledge of the genetic framework of adiposity and related measures. It is necessary to examine more advanced adiposity measures, specifically of relevance to abdominal adiposity, a major risk factor for cardiometabolic disorders among Asians. Moreover, in spite of being one continent, there is diversity among different ethnicities across Asia in terms of lifestyle, climate, geography, genetic structure and consequently the phenotypic manifestations. Hence, it is also important to consider ethnic specific studies for identifying and validating reliable genetic variants of adiposity measures among Asians.

Polycyclic aromatic hydrocarbons in cooked (tandoori) chicken and associated health risk.

Tandoori cooking is a popular food preparation method in India involving a unique combination of grilling, baking, barbecuing, and roasting processes. This study determined the levels of 16 polycyclic aromatic hydrocarbons (PAHs) in tandoori chicken and assessed the associated health risk. The sum of 16 PAHs concentration ranged from 25.4 to 3733 µg/kg with an average of 440 ± 853 µg/kg. Analyzed samples demonstrated major contribution of 2, 3, and 4 ring PAHs. Diagnostic ratios identified combustion and high-temperature processes as the main source favoring PAHs generation in these samples. Benzo(a)pyrene equivalents and incremental lifetime cancer risk (ILCR) estimates for different population groups (boys, girls, adult males, adult females, elderly males, elderly females) associated with dietary intake of these products ranged from 6.88E-05 to 4.13E-03 and 1.63E-08 to 1.72E-06, respectively. Since the ILCR values fell within the safe limits (1E-06, i.e., nonsignificant), the consumption of tandoori chicken may be considered as safe. The study emphasizes the need for extensive studies on PAHs formation in tandoori food products.

Evaluation of genetic variants related to lipid levels among the North Indian population.

Background: A heavy burden of cardiometabolic conditions on low- and middle-income countries like India that are rapidly undergoing urbanization remains unaddressed. Indians are known to have high levels of triglycerides and low levels of HDL-C along with moderately higher levels of LDL-C. The genome-wide findings from Western populations need to be validated in an Indian context for a better understanding of the underlying etiology of dyslipidemia in India. Objective: We aim to validate 12 genetic variants associated with lipid levels among rural and urban Indian populations and derive unweighted and weighted genetic risk scores (uGRS and wGRS) for lipid levels among the Indian population. Methods: Assuming an additive model of inheritance, linear regression models adjusted for all the possible covariates were run to examine the association between 12 genetic variants and total cholesterol, triglycerides, HDL-C, LDL-C, and VLDL-C among 2,117 rural and urban Indian participants. The combined effect of validated loci was estimated by allelic risk scores, unweighted and weighted by their effect sizes. Results: The wGRS for triglycerides and VLDL-C was derived based on five associated variants (rs174546 at FADS1, rs17482753 at LPL, rs2293889 at TRPS1, rs4148005 at ABCA8, and rs4420638 at APOC1), which was associated with 36.31 mg/dL of elevated triglyceride and VLDL-C levels (ß = 0.95, SE = 0.16, p < 0.001). Similarly, every unit of combined risk score (rs2293889 at TRPS1 and rs4147536 at ADH1B) was associated with 40.62 mg/dL of higher total cholesterol (ß = 1.01, SE = 0.23, p < 0.001) and 33.97 mg/dL of higher LDL-C (ß = 1.03, SE = 0.19, p < 0.001) based on its wGRS (rs2293889 at TRPS1, rs4147536 at ADH1B, rs4420638 at APOC1, and rs660240 at CELSR2). The wGRS derived from five associated variants (rs174546 at FADS1, rs17482753 at LPL, rs4148005 at ABCA8, rs4420638 at APOC1, and rs7832643 at PLEC) was associated with 10.64 mg/dL of lower HDL-C (ß = -0.87, SE = 0.14, p < 0.001). Conclusion: We confirm the role of eight genome-wide association study (GWAS) loci related to different lipid levels in the Indian population and demonstrate the combined effect of variants for lipid traits among Indians by deriving the polygenic risk scores. Similar studies among different populations are required to validate the GWAS loci and effect modification of these loci by lifestyle and environmental factors related to urbanization.

Influence of pyrolysis temperature on biochar properties and Cr(VI) adsorption from water with groundnut shell biochars: Mechanistic approach.

This study was envisaged to understand the effect of increasing pyrolysis temperature on the Cr(VI) removal potential of the groundnut shells derived biochars. The biochars were prepared at four different pyrolysis temperatures (350 °C, 450 °C, 550 °C, 650 °C) and were used unmodified to examine the adsorption potential for Cr(VI). Influence of biochar dose (1-10 g/L), pHinitial (2-10), Cr(VI)initial (10-500 mg/L) on Cr(VI) adsorptions; adsorption kinetics and isotherms were investigated. The observations suggested that the pyrolysis temperature is the key player in deciding the physicochemical properties as well the adsorption potential of the biochars. SEM and FTIR analysis suggested significant morphological and functional transformations in biochars with increasing pyrolysis temperature. The pHinitial was found to be the most profound adsorption parameter determining the adsorption potential of the biochars. The Cr(VI) adsorption capacity of the biochars decreased with the increase of the pyrolysis temperature (142.87-31.25 mg/L) as well as the solution pHinitial. All the biochars attained 100% removal efficiency with 50 mg/L of Cr(VI)initial and GNSB/350 achieved it in the minimum time (10 h) among all the biochars. GNSB/350 showed promising Langmuir adsorption capacity of 142.87 mg/L (pH 2, Tadsorption 30 °C, Cr(VI)initial 10-500 mg/L). In addition, the adsorption mechanism was found to be a synergistic action of chemi/physi-sorption with monolayer adsorption. Hence, the pyrolysis temperature significantly altered the physicochemical properties of the biochars, which highly influenced the adsorption performance of biochars.

Integrated approach towards acrylamide reduction in potato-based snacks: A critical review.

Acrylamide is a process contaminant and neurotoxic with growing evidence of cancer in human. Potato-based products majorly contribute towards acrylamide dietary intake thereby posing major food safety threat that necessitates formulation of acrylamide reduction strategies. This review highlights the recent research work on acrylamide formation mechanism, dietary intake, toxicity and potential reduction strategies at various levels in the food supply chain to ensure safety of potato-based products. Acrylamide formation in potato-based products depends on several factors involved in potato supply chain. Depending on the variety, application of nitrogen and sulphur fertilization may show positive, negative, or no effect on acrylamide formation. Heat and water stress faced by potato crops may increase the risk of acrylamide formation in processed products. Various pre-processing (e.g., blanching, chemical treatments etc.) and processing (e.g., methods, temperature, time) strategies may also reduce acrylamide formation (37-98%) in potato-based products at commercial and domestic levels. The acrylamide reduction strategies from farm to fork level have been discussed with special emphasis on mechanism of chemical treatments with pictorial representation.

Persistent organic pollutants in foods, their interplay with gut microbiota and resultant toxicity.

Persistent Organic Pollutants (POPs) have become immensely prevalent in the environment as a result of their unique chemical properties (persistent, semi-volatile and bioaccumulative nature). Their occurrence in the soil, water and subsequently in food has become a matter of concern. With food being one of the major sources of exposure, the detrimental impact of these chemicals on the gut microbiome is inevitable. The gut microbiome is considered as an important integrant for human health. It participates in various physiological, biochemical and immunological activities; thus, affects the metabolism and physiology of the host. A myriad of studies have corroborated an association between POP-induced gut microbial dysbiosis and prevalence of disorders. For instance, ingestion of polychlorinated biphenyls, polybrominated diphenyl ethers or organochlorine pesticides influenced bile acid metabolism via alteration of bile salt hydrolase activity of Lactobacillus, Clostridium or Bacteroides genus. At the same time, some chemicals such as DDE have the potential to elevate Proteobacteria and Firmicutes/Bacteriodetes ratio influencing their metabolic activity leading to enhanced short-chain fatty acid synthesis, ensuing obesity or a pre-diabetic state. This review highlights the impact of POPs exposure on the gut microbiota composition and metabolic activity, along with an account of its corresponding consequences on the host physiology. The critical role of gut microbiota in impeding the POPs excretion out of the body resulting in their prolonged exposure and consequently, enhanced degree of toxicity is also emphasized.

A Topological Similarity Measure Between Multi-Resolution Reeb Spaces.

Searching similarity between a pair of shapes or data is an important problem in data analysis and visualization. The problem of computing similarity measures using scalar topology has been studied extensively and proven useful in the shape and data matching. Even though multi-field or multivariate (consists of multiple scalar fields) topology reveals richer topological features, research on building tools for computing similarity measures using multi-field topology is still in its infancy. In the current article, we propose a novel similarity measure between two piecewise-linear multi-fields based on their multi-resolution Reeb spaces - a newly developed data-structure that captures the topology of a multi-field. Overall, our method consists of two steps: (i) building a multi-resolution Reeb space corresponding to each of the multi-fields and (ii) proposing a similarity measure between two multi-resolution Reeb spaces by computing a list of topologically consistent matching pairs (of nodes) and the similarity between them. We demonstrate the effectiveness of the proposed similarity measure in detecting topological features from real time-varying multi-field data in two application domains - one from computational physics and one from computational chemistry.

Comparative analysis of conventional and greener extraction methods and method validation for analyzing PAHs in cooked chicken and roasted coffee.

This study compared different extraction methods [sonication, alkaline hydrolysis, supramolecular solvent microextraction (SUPRAS) and Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS)] along with their greenness. An analytical method was validated for determination of USEPA's listed 16 polycyclic aromatic hydrocarbons' (PAHs) in cooked chicken and roasted coffee using high pressure liquid chromatography-fluorescence detector (HPLC-FLD) with a C18 column. The recoveries with QuEChERS ranged between 62.26 and 103.85% (except Naphthalene and Fluorene) and 52.63-78.69% (except Naphthalene) for chicken and coffee respectively while poor recoveries were observed with conventional methods. With SUPRAS, heavy PAHs' recovery in chicken was 71.33-112.23%. Limits of detection (LOD) were 0.03-0.06 ng/mL, regression coefficient values were 0.97-0.99 for 6.25-37.50 ng/mL quantification range. Relative standard deviation was found to be below 22%. The time and energy consumption per sample was 42.50 and 69.06 fold and 77.52 and 139.50 fold less with SUPRAS and QuEChERS method respectively as compared to alkaline hydrolysis.

Quantification of polycyclic aromatic hydrocarbons in kitchen depositions by SUPRAS-LC-FLR and human health risk assessment.

Concentration, composition and sources of polycyclic aromatic hydrocarbons (PAHs) in kitchen depositions from different sampling categories such as restaurants, university mess and houses were investigated, and associated human exposure risk through dietary intake, inhalation and dermal contact was determined. The PAHs in the samples were extracted by supramolecular solvent based microextraction (SUPRAS) method and the concentrations were determined by high pressure liquid chromatography (HPLC) with fluorescence detection. The mean of Σ16PAHs concentration was found to be the highest (386.09 ± 413.17 mg kg-1) for restaurants followed by mess (80.91 ± 92.81 mg kg-1) and houses (24.65 ± 10.52 mg kg-1). Traffic sources were found to be predominant contributors of PAHs in restaurants while cooking activities were the sources for mess and houses. Three- and five-ring PAHs were prominent in restaurants and mess samples while two- and three-ring PAHs contributed the most in houses samples. Non-cancer risk (hazard index) from exposure to these PAHs was found to be within safe limits i.e. 2.70E-09 to 7.46E-08. Estimated lifetime cancer risk was found to range from 2.46E-06 to 7.81E-04 from exposure to these PAHs and indicates significant risk due to exceeding the guideline value of 10-6.

Causal relationships between lipid and glycemic levels in an Indian population: A bidirectional Mendelian randomization approach.

BACKGROUND: Dyslipidemia and abnormal glycemic traits are leading causes of morbidity and mortality. Although the association between the two traits is well established, there still exists a gap in the evidence for the direction of causality. OBJECTIVE: This study aimed to examine the direction of the causal relationship between lipids and glycemic traits in an Indian population using bidirectional Mendelian randomization (BMR). METHODS: The BMR analysis was conducted on 4900 individuals (2450 sib-pairs) from the Indian Migration Study. Instrument variables were generated for each lipid and glycemic trait (fasting insulin, fasting glucose, HOMA-IR, HOMA-ß, LDL-cholesterol, HDL-cholesterol, total cholesterol and triglycerides) to examine the causal relationship by applying two-stage least squares (2SLS) regression in both directions. RESULTS: Lipid and glycemic traits were found to be associated observationally, however, results from 2SLS showed that only triglycerides, defined by weighted genetic risk score (wGRS) of 3 SNPs (rs662799 at APOAV, rs780094 at GCKR and rs4420638 at APOE/C1/C4), were observed to be causally effecting 1.15% variation in HOMA-IR (SE = 0.22, P = 0.010), 1.53% in HOMA- ß (SE = 0.21, P = 0.001) and 1.18% in fasting insulin (SE = 0.23, P = 0.009). No evidence for a causal effect was observed in the reverse direction or between any other lipid and glycemic traits. CONCLUSION: The study findings suggest that triglycerides may causally impact various glycemic traits. However, the findings need to be replicated in larger studies.

Biochar synthesis from sweet lime peel for hexavalent chromium remediation from aqueous solution.

Sweet lime (Citrus limetta) peel biochar was obtained by slow pyrolysis of raw biomass at 450 °C with 5 °C/min heating rate. Proximate and ultimate analysis, physico-chemical characterization of the biochar was done. Batch adsorption experiments for Cr(VI) removal were performed with varying pH, biochar dose, contact time and initial Cr(VI) concentrations. It took 8-24 h to reach the equilibrium at 30 °C for varying Cr(VI) concentrations. The biochar was found to possess higher adsorption capacity (100 mg/g) than the adsorbents reported in several previous studies. Langmuir adsorption isotherm and pseudo second order model best explained the experimental data, suggesting monolayer adsorption as the dominant mechanism. Chemical interaction, ion exchange of solute and sorbate ions and physical adsorption also contributed into Cr(VI) adsorption process. Further, Cr(VI) adsorption was found to be a multistep process. The findings suggested that sweet lime peel biochar can be utilized as a low cost and efficient alternative for Cr(VI) removal, which could be useful for aqueous solutions, as well as to promote overall protection against soil and water degradation and pollution.

Gestational route to healthy birth (GaRBH): protocol for an Indian prospective cohort study.

INTRODUCTION: Pregnancy is characterised by a high rate of metabolic shifts from early to late phases of gestation in order to meet the raised physiological and metabolic needs. This change in levels of metabolites is influenced by gestational weight gain (GWG), which is an important characteristic of healthy pregnancy. Inadequate/excessive GWG has short-term and long-term implications on maternal and child health. Exploration of gestational metabolism is required for understanding the quantitative changes in metabolite levels during the course of pregnancy. Therefore, our aim is to study trimester-specific variation in levels of metabolites in relation to GWG and its influence on fetal growth and newborn anthropometric traits at birth. METHODS AND ANALYSIS: A prospective longitudinal study is planned (start date: February 2018; end date: March 2023) on pregnant women that are being recruited in the first trimester and followed in subsequent trimesters and at the time of delivery (total 3 follow-ups). The study is being conducted in a hospital located in Bikaner district (66% rural population), Rajasthan, India. The estimated sample size is of 1000 mother-offspring pairs. Information on gynaecological and obstetric history, socioeconomic position, diet, physical activity, tobacco and alcohol consumption, depression, anthropometric measurements and blood samples is being collected for metabolic assays in each trimester using standardised methods. Mixed effects regression models will be used to assess the role of gestational weight in influencing metabolite levels in each trimester. The association of maternal levels of metabolites with fetal growth, offspring's weight and body composition at birth will be investigated using regression modelling. ETHICS AND DISSEMINATION: The study has been approved by the ethics committees of the Department of Anthropology, University of Delhi and Sardar Patel Medical College, Rajasthan. We are taking written informed consent after discussing the various aspects of the study with the participants in the local language.

Concentration and factors affecting the distribution of phthalates in the air and dust: A global scenario.

Phthalates are ubiquitously present environmental contaminants. Air and dust are the most important mediums of exposure to phthalates. The present study reviews the presence of phthalates in the air and dust reported from different countries in the last ten years (2007-2017). The phthalate concentrations revealed wide heterogeneity with a mean and median value 6 ±â€¯19 µg/m3 and 0.5 µg/m3 respectively in the air and 1.5 × 103 ±â€¯2.2 × 103 µg/g and 7.8x102µg/g respectively in the dust. The highest phthalates levels in the air were reported from India (1.1 × 102 µg/m3) and in dust from Bulgaria (1.2 × 104 µg/g). Overall higher levels were reported from developing countries as compared to developed countries. Di (2-ethylhexyl) phthalate (DEHP) and Di-n-butyl phthalate (DBP) were found to be predominant in both air and dust. Temperature, humidity, air exchange rate, building material and indoor maintenance were reported as the important factors influencing the levels of phthalates in the air and dust. In addition to policy level interventions, reducing the use of phthalate containing materials and controlling the factors which enhance the emission from existing sources can help in reducing human exposure to phthalates.

PAHs in Indian diet: Assessing the cancer risk.

Food products such as bread, biscuits, tea, coffee, oils, chocolates, grapes, pepper and fishes belonging to different categories represent a significant part of everyday diet in India and other countries having variable cooking techniques. In this study, we evaluated cancer risks of long term exposure to polycyclic aromatic hydrocarbons (PAHs) through consumption of these products for eight societal groups in India. Total concentrations of PAHs in these products from India ranged from 0.18 to 61967 µg kg-1 and the cancer risk values for the eight sections of Indian population ranged between 7.63E-10 to 5.05E+00, indicating product specific distribution of risk from non-significant to significant levels. Cereals, vegetables and decoctions contributed majorly to cancer risk and the most susceptible group identified was children. The spread of risk estimates followed Burr and Exponential distributions. To the best of our knowledge, this is the first study to develop information on the health risk faced by Indian population through dietary PAHs.

Polycyclic aromatic hydrocarbons' formation and occurrence in processed food.

Polycyclic aromatic hydrocarbons (PAHs) emerged as an important contaminant group in a gamut of processed food groups like dairy, nuts, herbs, beverages, meat products etc. Different cooking processes and processing techniques like roasting, barbecuing, grilling, smoking, heating, drying, baking, ohmic-infrared cooking etc. contribute towards its formation. The level of PAHs depends on factors like distance from heat source, fuel used, level of processing, cooking durations and methods, whereas processes like reuse, conching, concentration, crushing and storage enhance the amount of PAHs in some food items. This review paper provides insight into the impact of dietary intake of PAHs, its levels and formation mechanism in processed food items and possible interventions for prevention and reduction of the PAHs contamination. The gaps and future prospects have also been assessed.

Dynamics of toxic heavy metals in different compartments of a highly urbanized closed aquatic system.

This paper deals with the dynamics of chromium, nickel, copper and lead among the different components namely water, surface sediments, submerged and free floating macrophytes and fish of the twin manmade lakes, Upper and Lower lakes, of Bhopal (M.P., India). Some basic parameters of water and sediment have also been studied. The basin of the lake system is densely populated and the water is used for various purposes including drinking. Ni and Pb along with nitrate in both lakes are significantly higher than the drinking water quality criteria of USEPA. The concentration of the metals in the sediments is noticeably higher than that present in the adjoining rock, particularly Ni and Pb. There is a significant uptake of metals by the macrophytes (Eichhornia crassipes and Hydrilla verticillata) and fish (Labeo rohita and Oreochromis niloticus) mainly in summer. The fish of Lower lake (O. niloticus) is unfit for human consumption. The data have been statistically treated. Principle component analysis and cluster analysis were performed to define the origin of metals and to assess the relationship among the sites. Overall the Lower lake is more polluted than the Upper lake. In aggregate, the lake system is under an environmental stress due to certain practices.

Has the burden and distribution of PCBs and PBDEs changed in European background soils between 1998 and 2008? Implications for sources and processes.

Background soils were collected from 70 locations on a latitudinal transect in the United Kingdom and Norway in 2008, ten years after they had first been sampled in 1998. The soils were analyzed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCs), to see whether there had been any change in the loadings or distributions of these persistent organic pollutants (POPs). The same transect has also been used to sample air between the mid-1990s and the present, so the air and soil spatial and temporal trends provide information on air-soil transfers, source-receptor relationships, long-range atmospheric transport (LRAT), and recycling phenomena. Comparisons of the 2008 and 1998 data sets show a general decline for PBDEs in surface soil, and a smaller averaged net decline of PCBs. Changes between the years were observed for total POP concentrations in soil and also for correlations with site and sample characteristics assumed to affect those concentrations. POP concentrations were correlated to distance and strength of possible sources, a relationship that became weaker in the 2008 data. Fractionation, a commonly discussed process for the global cycling of POPs was also lost in the 2008 data. As in 1998, soil organic matter content continues to have a strong influence on the loadings of POPs in surface soils, but changes in the PCB loads were noted. These factors indicate an approach to air-surface soil equilibrium and a lessening of the influence of primary sources on POP concentrations in soil between 1998 and 2008.

Contrasting temporal trends and relationships of total organic carbon, black carbon, and polycyclic aromatic hydrocarbons in rural low-altitude and remote high-altitude lakes.

Historical records of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAHs) were reconstructed in dated sediment cores from four nearby lakes in central Switzerland. In the sub-Alpine Lake Thun, located at 558 m a.s.l., the proximity to anthropogenic emission sources is reflected in higher input of BC and PAHs into sediments with fluxes only slightly decreasing during the last decades. PAH/BC ratios are relatively high and correlation between levels of total PAHs and BC is almost inexistent in Lake Thun, probably due to the presence of less condensed forms of the BC spectrum (char BC) that is underestimated with the chemothermal oxidation method applied in this study. The sediment profiles of TOC, BC, and PAHs are noticeably different in the mountain lakes located around 2000 m a.s.l. In Lake Engstlen, the PAH/BC ratios, as well as the correlation between PAHs and BC, point towards appreciable amounts of predominantly light soot particles. Light soot particles have higher mobility and can, therefore, be efficiently transported to this remote site. The proglacial Lake Oberaar is shown to be a receptor of BC and PAHs released by the fast melting adjacent glacier acting as a secondary source for these conservative species temporarily stored in the glacier ice. Finally, Lake Stein is in strong contrast to all other lakes. High flux of BC into Lake Stein, combined with constant temporal evolutions of BC and PAHs, and in particular BC/TOC ratios approaching 100% are all strong indications for a geogenic presence of graphite in its catchment area.