Inhalation and ingestion of Synthetic musks in pregnant women: In silico spontaneous abortion risk evaluation and control.

Synthetic musks (SMs) are odor additives commonly used in the personal care products. Their wide existence in the environment and the recently reported adverse impact on the production and activity of progesterone and estrogen have raised pregnancy red flags and even lead to a pregnancy loss. Apart from the suggestion of limiting SM contact and exposure, effective abortion risk control measures for SMs remain to be blank. Facing the above challenges, this study tried to establish a new theoretical circumvention strategy to reduce the abortion risk of SMs to pregnant women by designing the supplementary diet plan and environmentally friendly SMs derivatives using molecular docking and three-dimensional quantitative structure-activity relationship (3D-QSAR) models. According to the supplementary diet plan, the diet combination of vitamin E, vitamin B2, niacin, vitamin A, and vitamin B6 were confirmed to not only provide essential nutrients for human health, but also reduce the abortion risk in pregnant women in daily life. The multi-activity (binding ability of SMs with progesterone-estrogen) 3D-QSAR model was constructed to screen SMs derivatives. The LibDock score, a parameter reflecting the binding ability between SMs' Derivative-24 with progesterone-estrogen, decreased as much as 137.67% compared with its precursor galaxolide (HHCB). The 3D-QSAR models assisted screening indicated that Derivative-24 had lower environmental impacts (i.e., bioconcentration and mobility) and improved functional properties (odor stability, musky scent, and odor intensity). The integration of the optimum candidate, Derivative-24, with optimum three supplementary diet plans exhibited a much lower abortion risk than HHCB, demonstrating the effectiveness of the proposed theoretical circumvention strategy as a comprehensive abortion risk control measure. It also shed light on the design of new pharmaceutical and personal care products using advanced computing tools.

Impact of economic freedom on air pollution: configuration analysis of Asia-Pacific region.

Air pollution brings uncountable serious influences on human life during the last decade. This study is an attempt to compare economic liberalism with economic federalism in examining the problem of air pollution in the Asia-Pacific region. Economic analysts have different views with one school of thought arguing that air pollution is the cause of the failure of a free economy rather than the failure of government regulations, while another supports liberal economics and vice versa. After developing a conceptual framework, the study uses the technique of fuzzy set qualitative comparative analysis (fsQCA) to examine how the rule of law, the size of government, regulatory efficiency, and the openness of the market influence air pollution in countries across the region. The analysis identifies two solutions with government size being found to be a necessary and core condition that influences air pollution. The study thus provides insights and suggests that government spending, taxation, and other financial health policies can be used as key sources to control air pollution in the Asia-Pacific region.

Reducing the dimension of water quality parameters in source water: An assessment through multivariate analysis on the data from 441 supply systems.

In this research, multivariate statistical analysis was performed on twenty water quality parameters (WQP) collected on tri-monthly basis (four times/year) from 441 drinking water sources in Newfoundland and Labrador (NL), Canada for 18 years (1999-2016). The WQP included alkalinity (Alk), color (Col), conductivity (Cond), hardness (Hard), pH, total dissolved solids (TDS), turbidity (Turb), bromide (Br), calcium (Ca), chloride (Cl), fluoride (F), potassium (K), sodium (Na), sulfate (SO4), dissolved organic carbon (DOC), ammonia (NH3), nitrate (NO3), Kjeldahl nitrogen (N), total phosphorus (P) and magnesium (Mg). The assessment was conducted on surface water (SWS) and groundwater (GWS) sources separately. In SWS and GWS, number of samples analyzed for each WQP were in the ranges of 3434-6057 and 1915-1919 respectively. Averages of DOC and pH showed increasing trends (SWS: DOC = 0.0722 mg/L/year; pH = 0.0375 units/year; GWS: DOC = 0.0491 mg/L/year; pH = 0.0441 units/year) while the other WQP showed variable characteristics, which could increase treatment cost and deteriorate tap water quality. Strong correlations were observed for Ca-Hard (r = 0.97-0.98), TDS-Cond (r = 0.91-0.99) and Na-Cl (r = 0.87-0.96). In SWS, Alk had stronger correlations with Cond, Hard, pH, TDS, Ca and Mg (r = 0.62-0.94) than GWS (r = 0.56-0.63). Principal Component Analysis revealed separate clusters for DOC-Col, Na-Cl, TDS-Cond, Ca-Alk and Mg-Hard, indicating that these WQP moved together. In SWS and GWS, six principal components were significant (eigenvalue ≥ 1.0), and explained 74.8% and 72.9% of overall variances respectively. In Factor Analysis, six varifactors explained 73.4% and 70.5% of total variances in SWS and GWS respectively. For SWS and GWS, eleven and ten WQP, respectively explained these variances, indicating 45% and 50% data reduction respectively. The findings can assist in controlling water quality through monitoring reduced number of WQP, which is likely to minimize the monitoring cost.

Affordable and efficient adsorbent for arsenic removal from rural water supply systems in Newfoundland.

The fly ash from the Corner Brook Pulp and Paper (CBPP) mill was used in this study as the raw material for the preparation of a low-cost adsorbent for arsenic removal from the well water of Bell Island. The CBPP fly ash was physically activated in two different ways: (a) activation with pure CO2 (CAC) with the iodine number and methylene value of 704.53 mg/g and 292.32 mg/g, respectively; and (b) activation with a mixture of CO2 and steam (CSAC) with the iodine number and methylene value of 1119.98 mg/g and 358.95 mg/g, respectively, at the optimized temperature of 850 °C and the time of 2 h for both activations. The BET surface areas of the CAC and CSAC at the optimized conditions were 847.26 m2/g and 1146.25 m2/g, respectively. The optimized CSAC was used for impregnation with iron (III) chloride (FeCl3) with different concentrations (0.01 M to 1 M). The study shows that the adsorbent impregnated with 0.1 M FeCl3 is the most efficient adsorbent for arsenic removal. Isotherm analysis shows that the Langmuir model better describes the equilibrium behavior of the arsenic adsorption from both local well water and synthesized water compared to the other models. The maximum arsenic adsorption capacity was 35.6 µg/g of carbon for local well water and 1428.6 µg/g of carbon for synthesized water. Furthermore, the kinetic behavior of arsenic adsorption from synthesized and local well water was well depicted by the pseudo-second order kinetic model.

Fly ash based robust biocatalyst generation: a sustainable strategy towards enhanced green biosurfactant production and waste utilization.

Biosurfactants have been well recognized as an environmentally friendly alternative to chemical surfactants. However, their production remains challenging due to low productivity, short-term microbe stability and the potentially toxic by-products generated in the growth media. To overcome these challenges, the emerging biofilm-based biosynthesis was investigated in this study. A fresh insight into the biosynthesis process was provided through using waste fly ash as a carrier material. The biofilm produced by biosurfactant producer B. subtilis N3-1P attached onto the surface of fly ash acted as a robust and effective biocatalyst. Zeta potential analysis and scanning electron microscope (SEM) characterization were conducted to help unravel the biocatalyst formation. High-value biosurfactant products were then produced in an efficient and sustainable manner. Stimulation by a fly ash assisted biocatalyst on biosurfactant production was confirmed. The biosurfactant yield was boosted over ten times after 24 hours, at a fly ash dosage of 0.5%. The highest biosurfactant yield was achieved after five days, with a final productivity of 305 critical micelle dilution. The underlying mechanism of fly ash assisted biosurfactant production was tracked through it exerting an effect on the quorum sensing system. Fourier-transform infrared (FTIR) spectroscopy and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis demonstrated that the final biosurfactant product belonged to the lipopeptides. This research output is expected to accelerate the development of more effective bioreactors, and make a continuous contribution to high-value product generation and waste reduction.

Isolation of nitrate-reducing bacteria from an offshore reservoir and the associated biosurfactant production.

Biosurfactant producing nitrate-reducing bacteria (NRB) in anaerobic reservoir environments are closely associated with souring (H2S) control in the offshore oil and gas industry. Five NRB strains were screened from offshore produced water samples and all were identified as Pseudomonas stutzeri. Their biosurfactant producing abilities when fed on either glucose or glycerol media were investigated. P. stutzeri CX3 reduced the medium surface tension to 33.5 and 29.6 mN m-1, respectively, while growing on glucose or glycerol media. The CX3 strain was further inoculated to examine its growth performance, resulting in 32.4% and 94.5% of nitrate consumption over 228 hours of monitoring in two media, respectively. The composition analysis of the biosurfactant product generated by P. stutzeri CX3 was conducted through thin-layer chromatography, gas chromatography with a flame ionization detector (FID) and Fourier transform infrared spectroscopy (FT-IR). The biosurfactant product was identified as a mixture of a small part of lipopeptides and a large part of glycolipids while its critical micellar concentration (CMC) was as low as 35 mg L-1. The biosurfactant product demonstrated high stability over a wide range of temperature (4-121 °C), pH (2-10), and salinity (0-20% w/v) concentration. The results provided valuable technical and methodological support for effective offshore reservoir souring control and associated enhanced oil recovery activities.

Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries.

Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water.

Predicting bromide incorporation in a chlorinated indoor swimming pool.

The water in and air above swimming pools often contain high levels of disinfection byproducts (DBPs) due to chemical reactions between chlorine- or bromine-based disinfectants and organic/inorganic matter in the source water and released from swimmers. Exposure to these DBPs, though inevitable, can pose health threats to humans. In this study, DBPs in tap water (S1), and water from a chlorinated indoor swimming pool before (S2) and after swimming (S3) were measured. The brominated species constituted the majority of DBPs formed in S1, S2, and S3. Trihalomethanes (THMs) in S3 was 6.9 (range 2.9-11.1) and 1.4 (range 0.52-2.9) times those in S1 and S2, respectively; and the haloacetic acids (HAAs) in S3 was 4.2 (range 2.5-7.5) and 1.2 (range 0.6-2.6) times those in S1 and S2, respectively. The mean THMs in air above the swimming pool before (S2-A) and after swimming (S3-A) were 72.2 and 93.0 µg/m(3), respectively, and their ranges were 36.3-105.8 and 44.1-133.6 µg/m(3), respectively. The average percentages of bromide incorporation (BI) into THMs in S1, S2, and S3 were 3.0, 9.3, and 10.6 %, respectively; and the BI into HAAs in S1, S2, and S3 were 6.6, 12.0, and 12.2 %, respectively. Several models were trained for predicting the BI into THMs and HAAs. The results indicate that additional information is required to develop predictive models for BI in swimming pools.

Human health risk assessment due to global warming--a case study of the Gulf countries.

Accelerated global warming is predicted by the Intergovernmental Panel on Climatic Change (IPCC) due to increasing anthropogenic greenhouse gas emissions. The climate changes are anticipated to have a long-term impact on human health, marine and terrestrial ecosystems, water resources and vegetation. Due to rising sea levels, low lying coastal regions will be flooded, farmlands will be threatened and scarcity of fresh water resources will be aggravated. This will in turn cause increased human suffering in different parts of the world. Spread of disease vectors will contribute towards high mortality, along with the heat related deaths. Arid and hot climatic regions will face devastating effects risking survival of the fragile plant species, wild animals, and other desert ecosystems. The paper presents future changes in temperature, precipitation and humidity and their direct and indirect potential impacts on human health in the coastal regions of the Gulf countries including Yemen, Oman, United Arab Emirates, Qatar, and Bahrain. The analysis is based on the long-term changes in the values of temperature, precipitation and humidity as predicted by the global climatic simulation models under different scenarios of GHG emission levels. Monthly data on temperature, precipitation, and humidity were retrieved from IPCC databases for longitude 41.25 degrees E to 61.875 degrees E and latitude 9.278 degrees N to 27.833 degrees N. Using an average of 1970 to 2000 values as baseline, the changes in the humidity, temperature and precipitation were predicted for the period 2020 to 2050 and 2070 to 2099. Based on epidemiological studies on various diseases associated with the change in temperature, humidity and precipitation in arid and hot regions, empirical models were developed to assess human health risk in the Gulf region to predict elevated levels of diseases and mortality rates under different emission scenarios as developed by the IPCC.The preliminary assessment indicates increased mortality rates due to cardiovascular and respiratory illnesses, thermal stress, and increased frequency of infectious vector borne diseases in the region between 2070 and 2099.

Revised estimates for continuous shoreline fumigation: a PDF approach.

A probability density function (PDF) fumigation model is presented here to study the dispersion of air pollutants emitted from a tall stack on the shoreline. This work considers dispersion of the pollutants in the stable layer and within the thermal internal boundary layer (TIBL) proceeds independently. The growth of TIBL is considered parabolic with distance inland. Turbulence is taken as homogeneous and stationary. Dispersion of particles (contaminant) in lateral and vertical directions is assumed independent of each other. This assumption allows us to consider the position of particles in both directions as independent random variables. The lateral dispersion distribution within the TIBL is considered as Gaussian and independent of height. A skewed bi-Gaussian vertical velocity PDF is used to account for the physics of dispersion due to different characteristics of updrafts and downdrafts within the TIBL. We have used Weil (J.C. Weil, A diagnosis of the asymmetry in top-down and bottom-up diffusion using a Lagrangian stochastic model, J. Atmos. Sci., 47 (1990) 501-515) solutions to find out the parameters of this PDF. Incorporating finite Lagrangian integral time scale for the vertical velocity component, it is observed that it reduces the vertical dispersion in the beginning and moves the point of maximum concentration further downwind. Due to little dispersion in the beginning, there is more plume to be dispersed causing higher concentrations at large distances. The model has considered Weil and Brower's (J.C. Weil, P.R. Brower, Estimating convective boundary layer parameters for diffusion applications, Maryland Power Plant Siting Program Rep. PPSP-MP-48, Department of Natural Resources, Annapolis, MD, 1985, 37 pp.) convective limit to analyze dispersion characteristics within TIBL. The revised model discussed here is evaluated with the data available from the Nanticoke field experiment on fumigation conducted in summer of 1978 in Ontario, Canada. The results of revised model are in good agreement with the observed data.

An overview and analysis of site remediation technologies.

This paper presents an analysis of the site restoration techniques that may be employed in a variety of contaminated site cleanup programs. It is recognized that no single specific technology may be considered as a panacea for all contaminated site problems. An easy-to-use summary of the analysis of the important parameters that will help in the selection and implementation of one or more appropriate technologies in a defined set of site and contaminant characteristics is also included.

Landfarm performance under arid conditions. 1. Conceptual framework.

The primary disposal method for oily sludge in the Kingdom of Saudi Arabia, which is a major oil-exporting country in the world, is landfarming. It is an attractive method of oily sludge disposal in hot arid climatic conditions. Although landfarming technology was introduced to Saudi Arabia in 1982, no scientific studies have been conducted within the Kingdom to support this decision. The results presented in this paper are based on a comprehensive field experiment conducted under Saudi Arabian environmental conditions. Details of experimental setup and conceptual framework of degradation process based on field observations are presented in this paper. The paper also addresses kinetics of oily sludge degradation in landfarm cells under natural and enhanced conditions in the presence of water, nutrients, and tilling. The 12-month field study showed that weathering (evaporation) and not biodegradation is the overall dominant degradation mechanism occurring in landfarms in the study area. The results of this study showed that up to 76% of the oil and grease (O&G) in the sludge has been lost from soil as a result of weathering. However, the results of this study also indicated the primary mechanism for the loss of C17 and C18 alkanes as compared to branched alkanes was due to biodegradation.

Landfarm performance under arid conditions. 2. Evaluation of parameters.

Various parameters that influence the degradation processes in landfarming operations include moisture content, microbial density and composition, nutrients, and tilling. In this paper, a detailed evaluation of each parameter is presented based on field experiments. This paper also addresses kinetic of weathering, volatilization, and biodegradation mechanisms under natural attenuation and enhanced conditions including aeration in the soil pores by tilling; combined effects of tilling and nutrients in the soil; tilling and addition of waterto maintain a minimum moisture level; and combination of tilling, water, and nutrients. The effect of double loading under enhanced condition was also studied in this paper. The study shows that the tilling is very effective to to enhance the loss of oil and grease (O&G) fractions under arid conditions. However hydrocarbon loss in the absence of fertilizer and water was mainly due to weathering (volatilization). In the absence water and nutrients, the microbial counts were found to be low. The addition of water and fertilizer combined with the tilling helped in the significant reduction of O&G through both volatilization and biodegradation mechanisms with early reduction of n-alkanes through a biodegradation process followed by weathering. However, in order to determine the contribution of each of these two processes to the whole degradation, further work is required. The high loading rate resulted in retaining moisture content in the soil, and it delayed weathering and biodegradation. The high loading rate caused bacterial counts to increase, as it provided them with a plentiful source of food and water; however, it did not stimulate the biodegradation process for almost 6 months after the highest rate of sludge application to the soil.

Distribution of arsenic and copper in sediment pore water: an ecological risk assessment case study for offshore drilling waste discharges.

Due to the hydrophobic nature of synthetic based fluids (SBFs), drilling cuttings are not very dispersive in the water column and settle down close to the disposal site. Arsenic and copper are two important toxic heavy metals, among others, found in the drilling waste. In this article, the concentrations of heavy metals are determined using a steady state "aquivalence-based" fate model in a probabilistic mode. Monte Carlo simulations are employed to determine pore water concentrations. A hypothetical case study is used to determine the water quality impacts for two discharge options: 4% and 10% attached SBFs, which correspond to the best available technology option and the current discharge practice in the U.S. offshore. The exposure concentration (CE) is a predicted environmental concentration, which is adjusted for exposure probability and bioavailable fraction of heavy metals. The response of the ecosystem (RE) is defined by developing an empirical distribution function of predicted no-effect concentration. The pollutants' pore water concentrations within the radius of 750 m are estimated and cumulative distributions of risk quotient (RQ=CE/RE) are developed to determine the probability of RQ greater than 1.

Water quality evaluation and trend analysis in selected watersheds of the Atlantic region of Canada.

Water quality indices (WQIs) have been developed to assess the suitability of water for a variety of uses. These indices reflect the status of water quality in lakes, streams, rivers, and reservoirs. The concept of WQIs is based on a comparison of the concentration of contaminants with the respective environmental standards. The number, frequency, and magnitude by which the environmental standards for specific variables are not met in a given time period are reflected in WQIs. Further, the water quality trend analysis predicts the behavior of the water quality parameters and overall water quality in the time domain. In this paper, the concept of WQI was applied to three selected watersheds of Atlantic region: the Mersey River, the Point Wolfe River, and the Dunk River sites. To have robust study, two different water quality indices are used: Canadian Water Quality Index (CWQI), and British Columbia Water Quality Index (BWQI). The complete study was conducted in two steps. The first step was to organize and process the data into a format compatible with WQI analysis. After processing the input data, the WQI was calculated. The second step outlined in the paper discusses detailed trend analysis using linear and quadratic models for all the three sites. As per the 25 years trend analysis, overall water quality for agriculture use observed an improving trend at all the three sites studied. Water quality for raw water used for drinking (prior to treatment) and aquatic uses has shown improving trend at Point Wolfe River. It is further observed that pH, SO4, and NO3 concentrations are improving at Dunk River, Mersey River, and Point Wolfe River sites. To ascertain the reliability and significance of the trend analysis, a detailed error analysis and parametric significance tests were also conducted. It was observed that for most of the sites and water uses quadratic trend models were a better fit than the linear models.

Landfarming operation of oily sludge in arid region--human health risk assessment.

Landfarming is becoming one of the most preferred treatment technologies for oily sludge disposal in the Arabian Gulf region in general, and in the Kingdom of Saudi Arabia in particular. This technology is considered to be, economical, energy efficient, and environmentally friendly with minimal residue disposal problems. Application of this technology in the region is simply based on the studies conducted in the United States of America and Europe. There have hardly been any scientific studies conducted to evaluate performance of landfarming technology under arid conditions. Recently, detailed field experimental study has been conducted to evaluate the degradation process and health risk issues in landfarming under arid conditions. The study observed volatilization as the main process of hydrocarbon degradation, which can cause significantly high concentration of airborne volatile organic compounds (VOCs) in the atmosphere leading to serious human health risk to the onsite workers. It is particularly true in the early phase of the landfarming process (first 2 months from initial loading). This paper elaborates these findings in detail.

Evaluation of generic types of drilling fluid using a risk-based analytic hierarchy process.

The composition of drilling muds is based on a mixture of clays and additives in a base fluid. There are three generic categories of base fluid--water, oil, and synthetic. Water-based fluids (WBFs) are relatively environmentally benign, but drilling performance is better with oil-based fluids (OBFs). The oil and gas industry developed synthetic-based fluids (SBFs), such as vegetable esters, olefins, ethers, and others, which provide drilling performance comparable to OBFs, but with lower environmental and occupational health effects. The primary objective of this paper is to present a methodology to guide decision-making in the selection and evaluation of three generic types of drilling fluids using a risk-based analytic hierarchy process (AHP). In this paper a comparison of drilling fluids is made considering various activities involved in the life cycle of drilling fluids. This paper evaluates OBFs, WBFs, and SBFs based on four major impacts--operations, resources, economics, and liabilities. Four major activities--drilling, discharging offshore, loading and transporting, and disposing onshore--cause the operational impacts. Each activity involves risks related to occupational injuries (safety), general public health, environmental impact, and energy use. A multicriteria analysis strategy was used for the selection and evaluation of drilling fluids using a risk-based AHP. A four-level hierarchical structure is developed to determine the final relative scores, and the SBFs are found to be the best option.

Risk-based process safety assessment and control measures design for offshore process facilities.

Process operation is the most hazardous activity next to the transportation and drilling operation on an offshore oil and gas (OOG) platform. Past experiences of onshore and offshore oil and gas activities have revealed that a small mis-happening in the process operation might escalate to a catastrophe. This is of especial concern in the OOG platform due to the limited space and compact geometry of the process area, less ventilation, and difficult escape routes. On an OOG platform, each extra control measure, which is implemented, not only occupies space on the platform and increases congestion but also adds extra load to the platform. Eventualities in the OOG platform process operation can be avoided through incorporating the appropriate control measures at the early design stage. In this paper, the authors describe a methodology for risk-based process safety decision making for OOG activities. The methodology is applied to various offshore process units, that is, the compressor, separators, flash drum and driers of an OOG platform. Based on the risk potential, appropriate safety measures are designed for each unit. This paper also illustrates that implementation of the designed safety measures reduces the high Fatal accident rate (FAR) values to an acceptable level.