Evaluation of metals release from oil sands coke : an ecotoxicological assessment of risk and hazard to aquatic invertebrates

The oil sands operations in northeast Alberta, Canada, employ unconventional processes to produce synthetic crude oil (SCO). Because the extracted bitumen, ¡®the form of oil in oil sands¡¯, is highly viscous, it requires thermal upgrading to produce SCO. Coking technology is used to convert heavy bitumen fractions to lighter volatile fractions. During this process, an enormous volume of solid coke is produced and the metal impurities (e.g. Al, Fe, Mn, Ni, Ti and V) present in bitumen fractions end-up in the coke particles. As coke demands significant space for storage, oil sands companies are exploring options for placing coke into reclamation landscapes for long term storage and recovery. However, coke holds appreciable amounts of potentially leachable metals that may impede the performance of reclamation landscapes. Although two previous coke leaching studies had showed that coke released metals into water at concentrations exceeding the Canadian guidelines for the protection of aquatic life, the ecotoxicological hazard and risk of these metals were not well characterized. Therefore, the overall goal of this research was to characterize the fate and toxicity of metals associated with coke. In this research, the toxicity of coke leachates collected from oil sands field sites and those artificially generated in the laboratory were evaluated using a standard three-brood Ceriodaphnia dubia tests. Coke leachates (CLs) collected over a period of 20 months from two field lysimeters were found to be acutely toxic to C. dubia. Vanadium concentrations were significantly higher (p¡Ü0.05) than concentrations of all other metals in CLs from both lysimeters, and also in leachates from a laboratory batch renewal leaching study. Furthermore, toxic unit (TU) calculations suggested that Ni and V were likely the cause of CL toxicity, but this was not explicitly proven. Therefore, a chronic toxicity identification and evaluation (TIE) approach was adopted to identify and confirm the cause(s) of CL toxicity. Coke was subjected to a 15 day batch leaching process in the laboratory at pH 5.5 and 9.5 in order to characterize the effect of pH on metals release from coke, and to generate CLs for use in TIE tests. The 7-day LC50 estimates for C. dubia survival were 6.3% and 28.7% (v/v) for CLs generated at pH 5.5 and 9.5, respectively. The dissolved concentrations of Mn, Ni and Zn were high (p¡Ü0.05) in pH 5.5 CL, whereas Al, Mo and V were high (p¡Ü0.05) in pH 9.5 CL. Evidence gathered from a series of chronic TIE tests revealed that Ni and V were the cause of toxicity in pH 5.5 CL, whereas V was the primary cause of toxicity in pH 9.5 CL. Further, the influence of bicarbonate, chloride and sulfate ions on metals release, speciation and Ni and V toxicity was investigated. The type and amount of metals released from coke was significantly influenced by the ion type elevated in the leaching solution. Specifically, sulfate influenced mobilization of Ni, Fe, Mn and Zn from coke, whereas bicarbonate enhanced Al, Mo and V releases from coke. With respect to toxicity, increasing bicarbonate decreased the 7-day Ni2+ IC50 from 6.3 to 2.3 ¦Ìg Ni2+/L suggesting enhanced Ni toxicity at high pH or alkalinity. Conversely, sulfate showed a protective effect against V toxicity to C. dubia. The research presented in this thesis suggests that coke will not be inert when stored in reclamation landscapes and that metals, particularly Ni and V, could reach ecotoxicologically relevant levels in surface waters or substrate porewaters, under favourable leaching conditions. Operationally, efforts should focus on remediation and monitoring of metals released from coke, particularly Ni and V, in impacted wetlands, especially before discharging water into natural wetlands and/or local streams and rivers

A review of human biomonitoring in selected Southeast Asian countries

Rapid development and industrialization in Southeast (SE) Asia has led to environmental pollution, potentially exposing the general population to environmental contaminants. Human biomonitoring (HBM), measurement of chemical and/or their metabolites in human tissues and fluids, is an important tool for assessing cumulative exposure to complex mixtures of chemicals and for monitoring chemical exposures in the general population. While there are national HBM programs in several developed countries, there are no such national programs in most of the SE Asian countries. However, in recent years there has been progress in the field of HBM in many of the SE Asian countries. In this review, we present recent HBM studies in five selected SE Asian countries: Bangladesh, Indonesia, Malaysia, Myanmar and Thailand. While there is extensive HBM research in several SE Asian countries, such as Thailand, in other countries HBM studies are limited and focus on traditional environmental pollutants (such as lead, arsenic and mercury). Further development of this field in SE Asia would be benefited by establishment of laboratory capacity, improving quality control and assurance, collaboration with international experts and consortiums, and sharing of protocols and training both for pre-analytical and analytical phases. This review highlights the impressive progress in HBM research in selected SE Asian countries and provides recommendations for development of this field.The work of the first author was supported by the Environment and Health Fund, Jerusalem, Israel.S

A standardized extract of Echinacea purpurea containing higher chicoric acid content enhances immune function in murine macrophages and cyclophosphamide-induced immunosuppression mice

AbstractContext Preparations of Echinacea have been used by herbalists to boost the immune system.Objective In this study, Echinacea purpurea (L.) Moench (Asteraceae) extract with enriched chicoric acid content was investigated for immunomodulation.Materials and methods The standardized hydroalcoholic extract (4% chicoric acid) was prepared from the aerial parts of E. purpurea (SEP). The extract was screened for in vitro antioxidant activities, and immunomodulation in RAW 264.7 cells, at 200 and 400 µg/mL. Further, the male BALB/c mice (20-25 g) were divided into 4 groups (n = 6 per group). All the groups except control, were intraperitoneally injected with 70 mg/kg/day of cyclophosphamide (CTX) for 4 consecutive days. The treatment groups received SEP extract (100 and 200 mg/kg body weight) p.o. from day 5 to 14.Results The SEP extract inhibited DPPH (IC50 = 106.7 µg/mL), ABTS+ (IC50 = 19.88 µg/mL) and nitric oxide (IC50 = 120.1 µg/mL). The SEP extract’s ORAC (oxygen radical absorbance capacity) value was 1931.63 µM TE/g. In RAW 264.7 cells, SEP extract increased the nitric oxide production by 30.76- and 39.07-fold at 200 and 400 µg/mL, respectively, compared to the untreated cells. SEP extract significantly increased phagocytosis and cytokine release (TNF-α, IL-6, and IL-1β) in the cells. Further, the extract improved immune organ indices, lymphocyte proliferation and serum cytokine levels in CTX-induced mice. The extract at 200 mg/kg significantly increased the natural killer cell activity (24.6%) and phagocytic index (28.03%) of CTX mice.Conclusion Our results strongly support SEP extract with 4% chicoric acid as a functional ingredient for immunomodulation

Evaluation of health risks associated with exposure to volatile organic compounds from household fuel combustion in southern India

Volatile organic compounds (VOCs) from household cook-fuel use are a major public health concern in low and middle income countries (LMICs), but health risk assessments have largely been based on measurements of fine particulate matter. We report results from cooking period measurements of 21 non-methane VOCs (NMVOCs) and estimated lifetime cancer risk for women cooks in the Tamil Nadu Air Pollution and Health Effects (TAPHE) cohort in Southern India. We enrolled 112 (56 biomass, 23 kerosene and 33 liquefied petroleum gas (LPG) using) TAPHE households to perform kitchen area measurements during the cooking period. VOC samples were collected on mixed-bed sorbent thermal desorption tubes using low-volume air samplers and analyzed using automated thermal desorption on a GC-MS system. Pentafluorobenzene, 1,4-difluorobenzene and chlorobenzene-d5 were used as internal standards that provided recoveries ranging from 81.7% to 119.9%. Total VOC concentrations were 4617 µg/m3, 2839 µg/m3 and 1639 µg/m3 while total BTEXS (i.e. benzene, toluene, ethylbenzene, m,p-xylene, o-xylene and styrene) concentrations were 139 µg/m3,121 µg/m3 and 245 µg/m3 among biomass, LPG and kerosene using households, respectively. Sampling season, type of food cooked and kitchen ventilation were significantly associated with measured total NMVOC concentrations. Lifetime cancer risks were estimated to be 2.93 × 10−3, 1.55 × 10−4 and 8.18 × 10−5, for biomass, kerosene and LPG fuel users, respectively with 1,2,3-trichloropropane, benzene, 1,4-dichlorobenze, 1,2-dibromoethane and chloroform contributing maximally to excess cancer risks. Health risk assessments for women cooks in LMICs should be expanded to include NMVOCs as these risks may not be adequately addressed through measurements of fine particulate matter (PM2.5) pollution alone

Synthesis and biological evaluation of salicylic acid conjugated isoxazoline analogues on immune cell proliferation and angiogenesis

Mitogenicity is the ability of the natural or synthetic compounds to induce cell division or proliferation. A series of salicylic acid derivatives containing isoxazoline moiety (8a-j) were synthesized and their immunopharmacological activities targeting lymphocyte proliferation and angiogenesis were evaluated. The compounds 8a-j mitogenicity were investigated on immunological cells that include human peripheral blood lymphocytes and murine splenocytes in-vitro. The results implicate that among the series of 8a-j, compound 8e showed a potent proliferative response on both human and murine lymphocytes. The proliferative index of the compound 8e was comparable to the reference mitogen Con A and mitogenecity is due to increased secretion IL-2. In -vivo CAM and rat corneal angiogenesis assays were performed to assess the compound's effect on endothelial cell migration and proliferation which inferred that 8e also induces the proliferation of endothelial cells. The study reports the synthetic immunostimulatory and pro-angiogenic activity of novel mitogen 8e which could be translated into new drug in future

Heat Exposure among Adult Women in Rural Tamil Nadu, India.

Exposure to heat is associated with a substantial burden of disease and is an emerging issue in the context of climate change. Heat is of particular concern in India, which is one of the worlds hottest countries and also most populous, where relatively little is known about personal heat exposure, particularly in rural areas. Here, we leverage data collected as part of a randomized controlled trial to describe personal temperature exposures of adult women (40-79 years of age) in rural Tamil Nadu. We also characterize measurement error in heat exposure assessment by comparing personal exposure measurements to the nearest ambient monitoring stations and to commonly used modeled temperature data products. We find that temperatures differ across individuals in the same area on the same day, sometimes by more than 5 °C within the same hour, and that some individuals experience sharp increases in heat exposure in the early morning or evening, potentially a result of cooking with solid fuels. We find somewhat stronger correlations between the personal exposure measurements and the modeled products than with ambient monitors. We did not find evidence of systematic biases, which indicates that adjusting for discrepancies between different exposure measurement methods is not straightforward

The relationship between greenspace and personal exposure to PM2.5 during walking trips in Delhi, India.

The presence of urban greenspace may lead to reduced personal exposure to air pollution via several mechanisms, for example, increased dispersion of airborne particulates; however, there is a lack of real-time evidence across different urban contexts. Study participants were 79 adolescents with asthma who lived in Delhi, India and were recruited to the Delhi Air Pollution and Health Effects (DAPHNE) study. Participants were monitored continuously for exposure to PM2.5 (particulate matter with an aerodynamic diameter of less than 2.5 μm) for 48 h. We isolated normal day-to-day walking journeys (n = 199) from the personal monitoring dataset and assessed the relationship between greenspace and personal PM2.5 using different spatial scales of the mean Normalised Difference Vegetation Index (NDVI), mean tree cover (TC), and proportion of surrounding green land use (GLU) and parks or forests (PF). The journeys had a mean duration of 12.7 (range 5, 53) min and mean PM2.5 personal exposure of 133.9 (standard deviation = 114.8) μg/m3. The within-trip analysis showed weak inverse associations between greenspace markers and PM2.5 concentrations only in the spring/summer/monsoon season, with statistically significant associations for TC at the 25 and 50 m buffers in adjusted models. Between-trip analysis also indicated inverse associations for NDVI and TC, but suggested positive associations for GLU and PF in the spring/summer/monsoon season; no overall patterns of association were evident in the autumn/winter season. Associations between greenspace and personal PM2.5 during walking trips in Delhi varied across metrics, spatial scales, and season, but were most consistent for TC. These mixed findings may partly relate to journeys being dominated by walking along roads and small effects on PM2.5 of small pockets of greenspace. Larger areas of greenspace may, however, give rise to observable spatial effects on PM2.5, which vary by season

Inter- versus Intracity Variations in the Performance and Calibration of Low-Cost PM_2.5 Sensors: A Multicity Assessment in India

Low-cost sensors (LCSs) have revolutionized the air pollution monitoring landscape. However, the sensitivities of particulate matter (PM) LCS measurements to various particle microphysical properties and meteorological aspects warrant an accuracy investigation. We investigated the inter- and intracity variations in the accuracy of LCS-measured PM2.5 across geographically and demographically distinct Indian cities. The collocation data of PM2.5 (collected during March–April 2022) from an LCS (Atmos) and a reference-grade instrument (β attenuation monitor) from nine sites (across five cities) were analyzed. The root-mean-square error (RMSE) in the hourly mean raw (uncorrected) Atmos PM2.5 measurements varied significantly across the cities. The Atmos PM2.5 overestimated the reference-grade PM2.5 values in cities located in the Indo-Gangetic Plain (Chandigarh and New Delhi) but considerably underestimated the values in the city located in western India (Mumbai). In south Indian cities (Bengaluru and Chennai), the Atmos PM2.5 measurements were relatively close to the reference-grade PM2.5 measurements. Among various statistical calibration models trained to correct the Atmos PM2.5 measurements for most locations, a generalized additive model performed better than other models. The performance of the calibration models was investigated using the holdout cross-validation method. The correction models improved the accuracy of the Atmos PM2.5 measurements by up to 70%. The bias range of the intracity (Mumbai) raw Atmos PM2.5 measurements was approximately comparable to the intercity bias range. Across the study locations, the generalized additive model performed the best in correcting the raw LCS PM2.5 measurements. We also demonstrated that the application of the location-specific calibration model to correct Atmos PM2.5 measurements improved the accuracy of the LCS PM2.5 measurements compared with the application of a single-location calibration model for city-wide data