Petroleum contaminated water and health symptoms: a cross-sectional pilot study in a rural Nigerian community

Polycyclic aromatic hydrocarbons in fish (fresh and dried) and public health in Nigeria: a systematic review

In Nigeria, environmental pollution linked with PAHs has been increasing, and PAHs in fish pose a threat to all, especially those that rely upon fish. This systematic review aimed at evaluating human health effect of PAHs concentration in dried and fresh fish in Nigeria. A systematic literature search was carried out on PubMed, MedLine, Web of Science and Science Direct, etc. From the total of 31 articles reviewed, 19 studies reported on fresh fish and 9 on dried fish. 54.8% of the selected research reported on high-level PAH accumulation in fresh fish. PAH contamination was mainly from petrogenic and pyrogenic sources. The major health outcomes from this study were cancer and non-carcinogenic risks, skin irritations, gastrointestinal, child deformities, respiratory disorders, emotional distresses, neurological and haematological effects. It is recommended that regulations be made to abate and monitor the environmental exposure of humans to PAHs to ameliorate the public health effects.

Characterization and identification of long-chain hydrocarbon-degrading bacterial communities in long-term chronically polluted soil in Ogoniland: an integrated approach using culture-dependent and independent methods

Escalating oil consumption has resulted in an increase in accidental spills of petroleum hydrocarbons, causing severe environmental degradation, notably in vulnerable regions like the Niger Delta. Complex mixture of these hydrocarbons particularly long-chain alkanes presents unique challenges in restoration of polluted environment due to their chemical properties. This study aimed to investigate the long-chain hydrocarbon-degrading bacterial communities within long-term chronically polluted soil in Ogoniland, by utilizing both traditional cultivation methods and modern culture-independent techniques. Results revealed that surface-polluted soil (SPS) and subsurface soil (SPSS) exhibit significantly higher total organic carbon (TOC) ranging from 5.64 to 5.06% and total petroleum hydrocarbons (TPH) levels ranging from 36,775 ppm to 14,087 ppm, compared to unpolluted soil (UPS) with 1.97% TOC and 479 ppm TPH, respectively. Analysis of carbon chain lengths reveals the prevalence of longer-chain alkanes (C20-28) in the surface soil. Culture-dependent methods, utilizing crude oil enrichment (COE) and paraffin wax enrichment (PWE), yield 47 bacterial isolates subjected to a long-chain alkane degradation assay. Twelve bacterial strains demonstrate significant degradation abilities across all enriched media. Three bacterial members, namely Pseudomonas sp. (almA), Marinomonas sp. (almA), and Alteromonas (ladA), exhibit genes responsible for long-chain alkane degradation, demonstrating efficiency between 50 and 80%. Culture-independent analysis reveals that surface SPS samples exhibit greater species richness and diversity compared to subsurface SPSS samples. Proteobacteria dominates as the phylum in both soil sample types, ranging from 22.23 to 82.61%, with Firmicutes (0.2-2.22%), Actinobacteria (0.4-3.02%), and Acidobacteria (0.1-3.53%) also prevalent. Bacterial profiles at genus level revealed that distinct variations among bacterial populations between SPS and SPSS samples comprising number of hydrocarbon degraders and the functional predictions also highlight the presence of potential catabolic genes (nahAa, adh2, and cpnA) in the polluted soil. However, culture-dependent analysis only captured a few of the dominant members found in culture-independent analysis, implying that more specialized media or environments are needed to isolate more bacterial members. The findings from this study contribute valuable information to ecological and biotechnological aspects, aiding in the development of more effective bioremediation applications for restoring oil-contaminated environments.

Adsorption and photodegradation of organic contaminants by silver nanoparticles: isotherms, kinetics, and computational analysis

In view of the widespread and distribution of several classes and types of organic contaminants, increased efforts are needed to reduce their spread and subsequent environmental contamination. Although several remediation approaches are available, adsorption and photodegradation technologies are presented in this review as one of the best options because of their environmental friendliness, cost-effectiveness, accessibility, less selectivity, and wider scope of applications among others. The bandgap, particle size, surface area, electrical properties, thermal stability, reusability, chemical stability, and other properties of silver nanoparticles (AgNPS) are highlighted to account for their suitability in adsorption and photocatalytic applications, concerning organic contaminants. Literatures have been reviewed on the application of various AgNPS as adsorbent and photocatalyst in the remediation of several classes of organic contaminants. Theories of adsorption have also been outlined while photocatalysis is seen to have adsorption as the initial mechanism. Challenges facing the application of silver nanoparticles have also been highlighted and possible solutions have been presented. However, current information is dominated by applications on dyes and the view of the authors supports the need to strengthen the usefulness of AgNPS in adsorption and photodegradation of more classes of organic contaminants, especially emerging contaminants. We also encourage the simultaneous applications of adsorption and photodegradation to completely convert toxic wastes to harmless forms.

Potential natural attenuation of petroleum hydrocarbons in fuel contaminated soils: Focusing on anaerobic fuel biodegradation involving microbial Fe(III) reduction

Liquid fossil fuels, collectively known as total petroleum hydrocarbons (TPHs), are highly toxic and frequently leak into subsurface environments due to anthropogenic activities. As an in-situ biological remedial option for TPH contamination, aerobic TPH biodegradation is limited due to oxygen's low solubility in water, and because it is consumed quickly by aerobic bacteria. Thus, we investigated the potential of anaerobic TPH degradation by indigenous fermenting bacteria and Fe(III)-reducing bacteria. Twenty 6-10 m soil cores were collected from a closed military base subject to ongoing TPH contamination since the 1980s. Physicochemical and microbial properties were determined at 0.5-m intervals in each core. To assess the relationship between TPH degradation and microbial Fe(III) reduction, soil samples were grouped into high-TPH (>500 mg kg-1) and high-Fe(II) (>450 mg kg-1), high-TPH and low-Fe(II), low-TPH and high-Fe(II), and low-TPH and low-Fe(II) groups. Alpha diversity was significantly lower in high-TPH groups than in low-TPH groups, suggesting that high TPH concentrations exerted a strong selective pressure on bacterial communities. In the high-TPH and low-Fe(II) group, fermenting bacteria, including Microgenomatia and Chlamydiae, were more abundant, suggesting that TPH biodegradation occurred via fermentation. In the high-TPH and high-Fe(II) group, Fe(III)-reducing bacteria, including Geobacter and Zoogloea, were more abundant, suggesting that microbial Fe(III) reduction enhances TPH biodegradation. In contrast, the fermenting and/or Fe(III)-reducing bacteria were not statistically abundant in the low-TPH groups.

Respiratory Health Effects of Pollution Due to Artisanal Crude-Oil Refining in Bayelsa, Nigeria

Purpose

Artisanal refining of crude oil has been associated with the manifestations of various health problems directly related to the release of particulate matter, including polycyclic aromatic hydrocarbons (PAHs), into the environment. This study thus assessed the respiratory health effects associated with being resident in areas where crude oil is artisanally refined in Bayelsa State.

Material and methods

This study utilized a comparative, cross-sectional design and was conducted in three communities in Bayelsa State. These included Sampou (a mildly exposed community), Nembe, and Gbarain (severely exposed communities). A sample population of 615 adults selected by multistage sampling completed the study instrument, which assessed data on their respiratory health. Environmental monitoring of the PAHs levels of the samples was done, and concentrations were determined using the gas chromatography/flame ionization detector (GC/FID). The Statistical Package for Social Sciences version 25 was used to conduct descriptive and inferential analyses.

Results

Findings revealed that the highest number of moderate to severe respiratory disease symptoms was experienced by respondents from Nembe 12 (41.4%), followed by those from Sampou 8 (27.6%), and then by those from Gbarain 9 (31.0%). Also, coughing that occurred mostly when lying down was found to be significantly prevalent among residents of Nembe [35 (47.9%); p-value: 0.016], among other symptoms. Respiratory disease symptoms were more likely to be found among females (p-value: 0.037), smokers (p-value: 0.002), and those having a low health risk perception related to PAHs exposure (p-value: 0.002).

Conclusion

Respondents from the three study sites had in the past 12 months experienced various respiratory disease symptoms, which could be directly related to their exposure to pollution from artisanal crude oil refining. Artisanal refining of crude oil should be continually dissuaded through unwavering enforcement of environmental health laws in order to further improve public and environmental health.

Community health impacts after a jet fuel leak contaminated a drinking water system: Oahu, Hawaii, November 2021

BACKGROUND

In 2021, a large petroleum leak contaminated a water source that supplied drinking water to military and civilians in Oahu, Hawaii.

METHODS

We conducted an Assessment of Chemical Exposures (ACE) survey and supplemented that information with complementary data sources: (1) poison center caller records; (2) emergency department visit data; and (3) a key informant questionnaire.

RESULTS

Among 2,289 survey participants, 86% reported ≥1 new or worsening symptom, 75% of which lasted ≥30 days, and 37% sought medical care. Most (n = 1,653, 72%) reported new mental health symptoms. Among equally observable symptoms across age groups, proportions of children ≤2 years experiencing vomiting, runny nose, skin rashes, and coughing (33, 46, 56, and 35%, respectively) were higher than other age groups. Poison center calls increased the first 2 weeks after the contamination, while emergency department visits increased in early December 2021. Key informant interviews revealed themes of lack of support, mental health symptoms, and long-term health impact concerns.

DISCUSSION

This event led to widespread exposure to petroleum products and negatively affected thousands of people. Follow-up health surveys or interventions should give special consideration to longer-term physical and mental health, especially children due to their unique sensitivity to environmental exposures.

Improving hydrocarbon toxicity tolerance in poultry: role of genes and antioxidants

Sustenance of smallholder poultry production as an alternative source of food security and income is imperative in communities exposed to hydrocarbon pollution. Exposure to hydrocarbon pollutants causes disruption of homeostasis, thereby compromising the genetic potential of the birds. Oxidative stress-mediated dysfunction of the cellular membrane is a contributing factor in the mechanism of hydrocarbon toxicity. Epidemiological studies show that tolerance to hydrocarbon exposure may be caused by the activation of genes that control disease defense pathways like aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2p45-related factor 2 (Nrf2). Disparity in the mechanism and level of tolerance to hydrocarbon fragments among species may exist and may result in variations in gene expression within individuals of the same species upon exposure. Genomic variability is critical for adaptation and serves as a survival mechanism in response to environmental pollutants. Understanding the interplay of diverse genetic mechanisms in relation to environmental influences is important for exploiting the differences in various genetic variants. Protection against pollutant-induced physiological responses using dietary antioxidants can mitigate homeostasis disruptions. Such intervention may initiate epigenetic modulation relevant to gene expression of hydrocarbon tolerance, enhancing productivity, and possibly future development of hydrocarbon-tolerant breeds.

A solar-driven degradation-evaporation strategy for membrane self-cleaning in the efficient separation of viscous crude oil/water emulsions

Membrane separation techniques are promising methods for effectively treating hazardous emulsified oily wastewater, but membrane fouling remains a serious challenge because the high viscosity and complex composition of crude oil make it easy to adhere to membranes and difficult to be removed by conventional physical or chemical cleaning means. Herein, a two-stage solar-driven (photo-Fenton degradation/evaporation) strategy was proposed to realize the self-cleaning of membranes fouled by viscous crude oil (>60,000 mPa s), wherein the photo-Fenton process helped to degrade the heavy components into light components, and all light components removed during the solar-driven evaporation process. A 1D/2D heterostructure membrane with photo-Fenton activity and anti-crude-oil-fouling performance was prepared via a facile self-assembly vacuum-assist method. The addition of rod-like g-C₃N₄ (RCN) increased the interlayer distance of α-FeOOH/porous g-C₃N₄ (FPCN) nanosheets, resulting in a high permeation flux. The FPCN-RCN membrane exhibited both high permeation flux of 779 ± 19 L m^-2h^-1bar^-1 and a separation efficiency of 99.4% for highly viscous crude oil-in-water emulsion. Importantly, the viscous crude oil fouled on the membrane was completely removed by the photo-Fenton degradation/solar-driven evaporation strategy, and the flux recovery rate of the membrane was ∼100%. Therefore, the FPCN-RCN membrane combined with the novel self-cleaning strategy exhibits great potential for practical emulsified oily wastewater treatment.

Effect of crude oil exploration and exploitation activities on soil, water and air in a Nigerian community

The continuous degradation of environmental ecosystems (land, water and soil) resulting from crude oil exploration and exploitation activities continues to gain global attention. This study investigates the effects of crude oil exploration and exploitation activities on soil, water and air in the study area. Soil samples were collected in three replicates at depths of 0-15 and 15-30 cm at sampling distances of 20, 100 and 200 m a from core oil exploitation operation area and a control point. Water samples were also taken from within the study area and analyzed using standard procedures. Major pollutants concentrations of particulate matter (PM_2.5 and PM₁₀) of the air were also measured using Air Quality Index (AQI). The results reveal that the soil, water and air parameters measured mostly at 20 m from the core oil operation area compromise the allowable standards provided for healthy living. In the same manner, some results at 100 and 200 m were slightly higher than the recommended values in some cases of heavy metals and bacteria activities in the soil. The AQI at 20 m was far above the permissible limit provided by the Environmental Protection Agency while others are gradually drawing towards the limit given for each pollutant. To safeguard the health of the residents of the host community and oil field workers, there is a need for proper and frequent environmental monitoring and assessment by authorized regulatory bodies in Nigeria. This will prevent any future exposure which may endanger the lives of the dwellers.

Latent Trajectories of Haematological, Hepatic, and Renal Profiles after Oil Spill Exposure: A Longitudinal Analysis

Exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in crude oil has carcinogenic effects on various organ systems. This longitudinal cohort study examined the effects of oil spill exposure on the haematological, hepatic, and renal profiles of Rayong oil spill clean-up workers. The sample included 869 clean-up workers from the Rayong oil spill. Latent class mixture models were used to investigate and classify the longitudinal trajectories and trends of the haematological, hepatic, and renal indices. Subgroup analysis was used to evaluate the association between the urinary metabolites of PAHs and VOCs and haematological, hepatic, and renal parameters. Most clean-up workers (97.6%) had increasing levels of white blood cells (WBCs) (0.03 × 103 cells/µL), 94.90% of the workers had a significantly increasing trend of blood urea nitrogen (0.31 mg/dL per year), and 87.20% had a significantly increasing trend of serum creatinine (0.01 mg/dL per year). A high-decreasing trend of WBCs was seen in 2.42% (-0.73 × 103 per year). Post-exposure changes in haematological, renal, and hepatic profiles are present in workers exposed to the Rayong oil spill. This indicates possible long-term health complications and worsening renal function after exposure to PAHs and VOCs in crude oil.

Comparison of O3, UV/O3, and UV/O3/PS processes for marine oily wastewater treatment: Degradation performance, toxicity evaluation, and flocs analysis

Efficient on-site treatment technology is crucial for mitigating marine oily wastewater pollution. This work investigates the ozone (O₃), ultraviolet (UV)/O₃, UV/O₃/persulfate (PS) processes for the treatment of marine oily wastewater, including degradation performance, acute toxicity evaluation, and oil flocs analysis in a benchtop circulating flow photoozonation reactor. Degradation performances have been studied by measuring the degradation rate of total oil concentrations, specific oil components (n-alkanes and polycyclic aromatic hydrocarbons (PAHs)), and total organic carbon (TOC). The results show that UV/O₃/PS could significantly enhance the removal efficiency than the other two processes, with above 90% of removal efficiency in 30 min. Acute toxicity analysis further shows that the wastewater quality is significantly improved by four-fold of the EC₅₀ of Vibrio fischeri, and the mortality of Artemia franciscana decreases from 100% to 0% after 48 h exposure. Further, the morphology and functional groups of flocs have been further characterized, showing that the floating flocs could be further degraded especially in UV/O₃/PS process. Our study further raised discussions regarding the future on-site application of O₃-based systems, based on the results generated from the treatment efficiency, toxicity, and flocs characterization. The regulation of the oxidation strength and optimization of the reaction systems could be a practical strategy for on-site marine oily wastewater treatment.

The effect of exposure to crude oil on the immune system. Health implications for people living near oil exploration activities

People who reside near oil exploration activities may be exposed to toxins from gas flares or oil spills. The impact of such exposures on the human immune system has not been fully investigated. In this review, research investigating the effects of crude oil on the immune system is evaluated. The aim was to obtain a greater understanding of the possible immunological impact of living near oil exploration activities. In animals, the effect of exposure to crude oil on the immune system depends on the species, dose, exposure route, and type of oil. Important observations included; hematological changes resulting in anemia and alterations in white blood cell numbers, lymph node and splenic atrophy, genotoxicity in immune cells, modulation of cytokine gene expression and increased susceptibility to infectious diseases. In humans, there are reports that exposure to crude oil can increase the risk of developing certain types of cancer and cause immunomodulation.Abbreviations: A1AT: alpha-1 antitrypsin; ACH₅₀: hemolytic activity of the alternative pathway; AHR: aryl hydrocarbon receptor; BALF: bronchoalveolar lavage fluid; COPD: chronic obstructive pulmonary disease; CYP: cytochrome P450; DNFB: 2, 4-dinitro-1-fluorobenzene; G-CSF: granulocyte-colony stimulating factor; IFN: interferon; IL: interleukin; 8-IP: 8-isoprostane; ISG15: interferon stimulated gene; LPO: lipid peroxidation; LTB₄: leukotriene B₄; M-CSF: macrophage-colony stimulating factor; MMC: melanomacrophage center; MPV: mean platelet volume; NK: natural killer; OSPM: oil sail particulate matter; PAH: polycyclic aromatic hydrocarbon; PBMC: peripheral blood mononuclear cell; PCV: packed cell volume; RBC: red blood cell; ROS: reactive oxygen species; RR: relative risk; T_H: T helper; TNF: tumour necrosis factor; UV: ultraviolet; VNNV: Viral Nervous Necrosis Virus; WBC: white blood cell.

Changes in neighborhood air quality after idling of an urban oil production site

Oil and gas development is occurring in urban, densely populated neighborhoods; however, the impacts of these operations on neighborhood air quality are not well characterized. In this research, we leveraged ambient air monitoring adjacent to an oil and gas production site in Los Angeles, California during active and idle periods. This study analyzed continuous methane (CH4) and non-methane hydrocarbon (NMHC) measurements, together with triggered grab samples and 24 hour integrated canister samples collected by the South Coast Air Quality Management District. Ambient air pollutant levels and trends were evaluated during active and idle well operations to assess changes in neighborhood air quality after the suspension of oil and gas production. We find that mean concentrations of methane, NMHC, benzene, toluene, ethylbenzene, xylenes, styrene, n-hexane, n-pentane, ethane, and propane decreased following the stop in production activities. Using a source apportionment approach, we observed that the "natural gas" drilling source contributed 23.7% to the total VOCs measured during the active phase, and only 0.6% to the total measured VOCs in the idle phase. Near urban oil and gas production sites, residents may face poorer air quality due to the oil and gas activities which may pose adverse health and environmental risks among proximate communities.

Another insight into the contamination levels at Ogoniland in Niger Delta, Nigeria, with focus on Goi Creek

Environmental pollution arising from crude oil exploratory activities has adversely impacted both the living and non-living components of the ecosystem. An insight into the impact of such activities with focus on Goi Creek in Ogoniland was provided in this study. We generated reliable data for physicochemical, heavy metal, and total hydrocarbon levels in the creek via a total of 40 samples collected across 4 stations designated within the creek in a duration of 10 months. With the exception of temperature, total dissolve solid, dissolved oxygen, chloride, sulfate, nitrate, zinc, and vanadium, the levels of other regulated parameters in the samples were not compatible with the national and international guidelines and standards for surface water quality including Federal Ministry of Environment Guidelines and standards for water quality in Nigeria and Environmental Protection Agency National recommended water quality criteria, respectively. The principal components (PCs) 1 and 2 of principal component analysis biplot revealed that the concentrations of the physicochemical parameters showed a mixed distribution among the stations; however, the heavy metals were more localized to station 4. Moreover, the dataset was subjected to water quality index (WQI), contamination index (C_d), heavy metal evaluation index (HEI), trace element toxicity index (TETI), and environmental water quality index (EWQI) to determine the extent of contamination. The result showed poor WQI, high contamination for C_d, and low-to-medium contamination for HEI. Although, there were variations among the stations on the contamination level, uniform remediation method should be adopted due to the similarity of the contaminants in all the stations.

Respiratory health, pulmonary function and local engagement in urban communities near oil development

BACKGROUND

Modern oil development frequently occurs in close proximity to human populations. Los Angeles, California is home to the largest urban oil field in the country with thousands of active oil and gas wells in very close proximity to homes, schools and parks, yet few studies have investigated potential health impacts. The neighborhoods along the Las Cienagas oil fields are situated in South LA, densely populated by predominantly low-income Black and Latinx families, many of whom are primarily Spanish-speakers.

METHODS

A cross-sectional community-based study was conducted between January 2017 and August 2019 among residents living <1000 m from two oil wells (one active, one idle) in the Las Cienagas oil field. We collected self-reported acute health symptoms and measured FEV1 (forced expiratory volume in the first second of exhalation) and FVC (forced vital capacity). We related lung function measures to distance and direction from an oil and gas development site using generalized linear models adjusted for covariates.

RESULTS

A total of 961 residents from two neighborhoods participated, the majority of whom identify as Latinx. Participants near active oil development reported significantly higher prevalence of wheezing, eye and nose irritation, sore throat and dizziness in the past 2 weeks. Among 747 valid spirometry tests, we observe that living near (less than 200 m) of oil operations was associated with, on average, -112 mL lower FEV1 (95% CI: -213, -10) and -128 mL lower FVC (95% CI: -252, -5) compared to residents living more than 200 m from the sites after adjustments for covariates, including age, sex, height, proximity to freeway, asthma status and smoking status. When accounting for predominant wind direction and proximity, we observe that residents living downwind and less than 200 m from oil operations have, on average, -414 mL lower FEV1 (95% CI: -636, -191) and -400 mL lower FVC (95% CI: -652, -147) compared to residents living upwind and more than 200 m from the wells.

CONCLUSIONS

Living nearby and downwind of urban oil and gas development sites is associated with lower lung function among residents, which may contribute to environmental health disparities.

Exposure and Public Health Effects of Polycyclic Aromatic Hydrocarbon Compounds in Sub-Saharan Africa: A Systematic Review

BACKGROUND AND AIM

In order to achieve improved global health, environmental health risks that could affect this goal have to be reduced as much as possible. This review thus aimed at determining the exposure levels, health risk assessments, and public health effects of polycyclic aromatic hydrocarbons (PAHs) in sub-Saharan Africa (SSA). This review was developed using guidelines provided for Preferred Reporting Items for Systematic Review and Meta-Analysis. Search was done on Google Scholar, Scopus, and PubMed databases. A study was included if it was carried out in SSA from 2000 to 2020 and written in English language. Fifty-two studies were finally retained and used for the review. Extracted data included the concentrations of 8 selected priority PAHs (including the PAHs prioritized for their carcinogenic potentials), their sources and reported outcomes. In SSA, PAHs exposure has been linked to the use of unprocessed biomass fuels for cooking, release of poorly treated petrochemical effluents into water bodies, and so on. Related public health effects included the occurrence of respiratory, cardiovascular abnormalities, and so on. Others included destruction of natural biodiversity in soil, water, and atmospheric environmental media. Health risk assessments also buttressed the occurrence of these public health effects of PAHs. In SSA, the region is exposed to a substantial amount of PAHs pollution which is associated with deleterious environmental and epidemiological effects. The adoption of healthier forms of energy, a change of attitude to one that favors environmental sustainability, and proper enforcement of environmental regulations are, however, necessary for attaining environmental sanity in SSA.

Toenail Metal Exposures in Fishermen from Bodo City, Nigeria

We conducted exposure assessment using toenails from 20 fishermen living in Bodo City, a community of the Niger delta region in Nigeria. This community has been affected by over 4000 oil spills and environmental disasters. Fishing is the primary source of food and income for individuals in this community. Previous research in Bodo City found elevated metal levels in fish. Toenails were used as a biomarker to investigate the feasibility for use in risk assessment studies in developing countries. The toenails collected had significantly higher manganese levels (median 5.8 µg/g) and lead levels (median 0.98 µg/g) than those reported in more developed countries, comparable levels to those from other low-middle incomes countries. These exposure levels are likely a direct result of exposures from the environmental disasters the community has experienced and would be related to increased risks for many diseases previously associated with heavy metal exposures.

Smartphone-based turbidity reader

Water quality is undergoing significant deterioration due to bacteria, pollutants and other harmful particles, damaging aquatic life and lowering the quality of drinking water. It is, therefore, important to be able to rapidly and accurately measure water quality in a cost-effective manner using e.g., a turbidimeter. Turbidimeters typically use different illumination angles to measure the scattering and transmittance of light through a sample and translate these readings into a measurement based on the standard nephelometric turbidity unit (NTU). Traditional turbidimeters have high sensitivity and specificity, but they are not field-portable and require electricity to operate in field settings. Here we present a field-portable and cost effective turbidimeter that is based on a smartphone. This mobile turbidimeter contains an opto-mechanical attachment coupled to the rear camera of the smartphone, which contains two white light-emitting-diodes to illuminate the water sample, optical fibers to transmit the light collected from the sample to the camera, an external lens for image formation, and diffusers for uniform illumination of the sample. Including the smartphone, this cost-effective device weighs only ~350 g. In our mobile turbidimeter design, we combined two illumination approaches: transmittance, in which the optical fibers were placed directly below the sample cuvette at 180° with respect to the light source, and nephelometry in which the optical fibers were placed on the sides of the sample cuvette at a 90^° angle with respect to the to the light source. Images of the end facets of these fiber optic cables were captured using the smart phone and processed using a custom written image processing algorithm to automatically quantify the turbidity of each sample. Using transmittance and nephelometric readings, our mobile turbidimeter achieved accurate measurements over a large dynamic range, from 0.3 NTU to 2000 NTU. The accurate performance of our smartphone-based turbidimeter was also confirmed with various water samples collected in Los Angeles (USA), bacteria spiked water samples, as well as diesel fuel contaminated water samples. Having a detection limit of ~0.3 NTU, this cost-effective smartphone-based turbidimeter can be a useful analytical tool for screening of water quality in resource limited settings.

Peat moss-derived biochars as effective sorbents for VOCs' removal in groundwater

Peat moss-derived biochars were produced at the pyrolytic temperatures of 300, 500, and 700 °C and were tested for evaluating the removal efficiency of volatile organic compounds (VOCs) from waters. As the pyrolytic temperature increases, the carbon contents were increased from 66 to 84%, and the contents of hydrogen and oxygen were decreased from 4 to 1% and from 19 to 4%, respectively. The surface areas of the biochars were 2 m² g^-1 at the pyrolysis temperature of 300 °C and were increased to 200 and 300 m² g^-1 at 500 and 700 °C, respectively. Results of FTIR analysis showed that functional groups such as hydroxyl, nitro, and carboxyl groups were observed in the biochar produced at 300 °C; however, the functional groups were removed in the biochars produced at higher temperatures. Sorption kinetics and equilibrium experiments were conducted with selected six VOCs of benzene (BZN), toluene (TOL), ethylbenzene (EBZ), p-xylene (pXYL), trichloroethylene (TCE), and tetrachloroethylene (PCE), which are the most common VOCs found in contaminated groundwater of South Korea. Sorption equilibrium was attained in 6 h with the constants of first order kinetic rate of 0.5 h^-1 for the VOCs tested. Freundlich isotherm well described the adsorption of VOCs to the biochars. Biochar produced at 500 °C showed the highest sorption capacity for all VOCs with an average K_f of 7692 (±2265), although biochars produced at 300 °C (K_f = 3146 ± 629) and 700 °C (K_f = 2776 ± 2693) showed the similar sorption capacity. The biochars produced at 500 °C can be an excellent remover of VOCs in contaminated groundwater.

The quality of public sources of drinking water in oil-bearing communities in the Niger Delta region of Nigeria

Background: Studies carried out in the Niger Delta region of Nigeria have demonstrated a link between oil exploration and poor-quality drinking water. However, many of these studies have been limited by small coverage and focus on few parameters. This study thus aimed at a comprehensive assessment of the quality of public sources of drinking water in three gas flaring and three non-gas flaring communities in the Niger Delta region of Nigeria. Methods: A total of 13 samples were collected from the major sources of drinking water in six communities in Rivers, Bayelsa and Delta States, Nigeria. These were stored and transported in line with International standards to a certified environmental laboratory where physical, chemical, bacteriological and petro-chemical assessments were conducted for 27 parameters. Results: Some samples had a pH below the normal range for drinking water, with median pH value of 4.63. All chemical parameters assessed fell below the normal acceptable range with exception of magnesium which exceeded the acceptable range. There were11 samples (91.7%) with microbial contamination; total and faecal coliform demonstrated at values ranging between 15 and 90 most probably number (MPN)/100 ml for total coliform and 9 to 23 MPN/100 ml for faecal coliforms. Oil, grease and total petroleum hydrocarbons (TPH) were identified in water samples from all communities. Values for oil and grease ranged between <0.001 and 0.015 mg/l, while TPH values were between <0.001 and 0.046 mg/l. There was no significant difference between median values in gas flaring and non-gas flaring communities. Conclusion: Distortion of physico-chemical properties, and hydrocarbon and faecal contamination of drinking water are a major challenge in oil-bearing communities in the Niger Delta region of Nigeria irrespective of gas flaring status. This calls for urgent interventions to improve the quality of drinking water for the people of the Niger Delta.

Accurate and Sensitive Determination Method for Procymidone and Chlorflurenol in Municipal Wastewater, Medical Wastewater and Irrigation Canal Water by GC-MS After Vortex Assisted Switchable Solvent Liquid Phase Microextraction

In this study, the detection power of a gas chromatography mass spectrometer (GC-MS) for procymidone and chlorflurenol was significantly enhanced using switchable solvent liquid phase microextraction (SS-LPME) as a preconcentration tool. This was achieved by a comprehensive optimization of significant parameters to the SS-LPME method such as switchable solvent amount, concentration and amount of sodium hydroxide, pH effect and mixing effect. The optimum experimental conditions obtained were used to determine analytical figures of merit for the analytes. The limits of detection obtained were 0.44 and 2.9 ng/mL for procymidone and chlorflurenol, respectively. The optimum method was applied to water sampled from an irrigation canal and two wastewater samples. The samples were spiked at two concentrations and the percent recovery results obtained ranged between 86 and 115% for both analytes. The recovery results together with the low standard deviations recorded validated the method as accurate and precise.

Impact of upstream oil extraction and environmental public health: A review of the evidence

Upstream oil extraction, which includes exploration and operation to bring crude oil to the surface, frequently occurs near human populations. There are approximately 40,000 oil fields globally and 6 million people that live or work nearby. Oil extraction can impact local soil, water, and air, which in turn can influence community health. As oil resources are increasingly being extracted near human populations, we highlight the current scope of scientific knowledge regarding potential community health impacts with the aim to help identify scientific gaps and inform policy discussions surrounding oil drilling operations. In this review, we assess the wide range of both direct and indirect impacts that oil drilling operations can have on human health, with specific emphasis on understanding the body of scientific literature to assess potential environmental and health risks to residents living near active onshore oil extraction sites. From an initial literature search capturing 2236 studies, we identified 22 human studies, including 5 occupational studies, 5 animal studies, 6 experimental studies and 31 oil drilling-related exposure studies relevant to the scope of this review. The current evidence suggests potential health impacts due to exposure to upstream oil extraction, such as cancer, liver damage, immunodeficiency, and neurological symptoms. Adverse impacts to soil, air, and water quality in oil drilling regions were also identified. Improved characterization of exposures by community health studies and further study of the chemical mixtures associated with oil extraction will be critical to determining the full range of health risks to communities living near oil extraction.

Sorption of benzene and naphthalene on (semi)-arid coastal soil as a function of salinity and temperature

Considerable activities from the oil and natural gas sector have risen some concerns about the pollution of soil and groundwater by petroleum hydrocarbons (PHCs) in (semi)-arid coastal regions. The understanding of the fate and transport of PHCs in these regions is therefore necessary to develop strategies for remediation. To quantify the sorption rates of PHCs in (semi)-arid coastal soil environments, we conducted a series of controlled-laboratory batch experiments under variable temperature and salinity conditions. The soil samples were collected from the eastern coast of Qatar which is near the two largest off-shore oil and natural gas fields of the country (North Gas and Al-Shaheen Oil Fields), and the volatile benzene and naphthalene were used as PHCs. The characterization of soil samples showed sand classification with the texture class of sabkha and saline beach sandy soils with calcite as potential dominant mineral. The concentrations of dissolved chloride and sodium were found to be high (> 400 mg L^-1) with a chloride-to‑sodium ratio of about 1.7. The results of sorption experiments showed that the rates of naphthalene sorption were more than for benzene, where the initial aqueous concentrations of benzene and naphthalene were reduced at equilibrium due to sorption by about 14-25% and 65-79%, respectively. This difference was attributed mainly to the organic carbon-water partitioning coefficient which is higher for naphthalene. The sorption rate experiments showed that sorption was stronger for benzene under higher salinity and lower temperature conditions. The sorption of naphthalene was not affected by the change in salinity but increased by 18% when the temperature decreased from 35 to 5 °C. A sorption kinetic model was also applied to define the sorption behavior of benzene and naphthalene for the coastal soil collected in Qatar and the best fits were achieved with the Langmuir sorption isotherm.

Elevated Indoor Volatile Organic Compound Exposure in the Niger Delta Region of Nigeria

The implications of environmental contamination on human health in the Niger Delta region of Nigeria remain a topic of growing international public health interest. To better understand ongoing air pollution and initiate remediation efforts, the United Nations Environmental Programme (UNEP) report recommended the monitoring of volatile organic compounds (VOCs) across different media (water, soil, and air) in Ogoniland, an at-risk population in the Niger Delta region of Nigeria. In this pilot study, we measured indoor VOC concentrations in the indoor air of 20 households in Ogale, an Ogoniland community whose groundwater system is contaminated with benzene at levels 900 times the World Health Organization guidelines and evaluated self-reported health conditions and predicted cancer risks and hazards from inhalation exposure to VOCs. We detected higher concentrations of benzene (mean = 25.7 μg/m³, SD = 23.2 μg/m³) and naphthalene (mean = 7.6 μg/m³, SD = 13.8 μg/m³) than has been reported in other regions. Although study participants reported health symptoms consistent with VOC exposure, we were underpowered to detect a significant association between select indoor VOCs and these self-reported health symptoms using univariate logistic regression models. These findings suggest that that the health symptoms reported by participants may be poor proxies for the underlying disease processes associated with adverse health outcomes due to VOC exposure in this community and that the burden of adverse health effects due to VOC exposure may stem from the contaminated groundwater system. We estimated a non-cancer hazard quotient of 3 from exposure to naphthalene and lifetime excess cancer risks from exposure to naphthalene, benzene, p-dichlorobenzene, carbon tetrachloride, and ethylbenzene of 3 × 10⁻⁴, 2 × 10⁻⁴, 6 × 10⁻⁵, 6 × 10⁻⁶, and 1 × 10⁻⁵, respectively. These results exceed common risk benchmarks in the United States, suggesting a need for further studies to characterize VOC exposures, sources, and associated health risks in the Niger Delta.

Is living in a gas-flaring host community associated with being hypertensive? Evidence from the Niger Delta region of Nigeria

Background

Researchers have linked gas flaring to climate change, the hastening of the epidemiological transition and an upsurge in the prevalence of non-communicable diseases. We sought to determine if a relationship exists between residing in a gas-flaring host community and hypertension.

Methods

We conducted an analytical cross-sectional household survey among residents of 600 households in three gas-flaring and three non-gas-flaring host communities in the Niger Delta region of Nigeria. We took geo-coordinates, administered a modified WHO-STEPS questionnaire and built on Android mobile phones using Open-Data-Kit (ODK) software. We also took biological measurements and carried out descriptive and inferential statistical analysis using SPSS and STATA.

Results

We interviewed a total of 912 adults: 437 (47.9%) from non-gas-flaring and 475 (52.1%) from gas-flaring host communities. There were differences in level of education (x2=42.99; p=0.00), occupation category (x2=25.42; p=0.00) and BMI category (x2=15.37; 0.003) among the two groups. The overall prevalence of hypertension was 23.7%: 20.7% among persons living in non-gas-flaring host communities compared with 25.3% among persons living in gas-flaring host communities (x2=2.89; p=0.89). Residence in a gas-flaring host community, (AdjOR=1.75; 95% CI=1.11 to 2.74) and mean age (AdjOR=1.05; 95% CI=1.03 to 1.07) were identified as the predictors of hypertension. There was a significant association between hypertension and age, 1.05 (1.04–1.06) while the probability of being hypertensive was higher among residents of gas-flaring host communities between 20 to 40 years and 60 to 80 years.

Conclusion

There is a need for the relevant agencies to scale up environmental and biological monitoring of air pollutants. The implication of a possible relationship between gas-flaring and hypertension brings to the fore the need for interventions to regulate gas-flaring activities.

Competing Forces of Socioeconomic Development and Environmental Degradation on Health and Happiness for Different Income Groups in China

China's rapid socioeconomic growth in recent years and the simultaneous increase in many forms of pollution are generating contradictory pictures of residents' well-being. This paper applies multilevel analysis to the 2013 China General Social Survey data on social development and health to understand this twofold phenomenon. Multilevel models are developed to investigate the impact of socioeconomic development and environmental degradation on self-reported health (SRH) and self-reported happiness (SRHP), differentiating among lower, middle, and higher income groups. The results of the logit multilevel analysis demonstrate that income, jobs, and education increased the likelihood of rating SRH and SRHP positively for the lower and middle groups but had little or no effect on the higher income group. Having basic health insurance had an insignificant effect on health but increased the likelihood of happiness among the lower income group. Provincial-level pollutants were associated with a higher likelihood of good health for all income groups, and community-level industrial pollutants increased the likelihood of good health for the lower and middle income groups. Measures of community-level pollution were robust predictors of the likelihood of unhappiness among the lower and middle income groups. Environmental hazards had a mediating effect on the relationship between socioeconomic development and health, and socioeconomic development strengthened the association between environmental hazards and happiness. These outcomes indicate that the complex interconnections among socioeconomic development and environmental degradation have differential effects on well-being among different income groups in China.

An in-depth survey of the oil spill literature since 1968: Long term trends and changes since Deepwater Horizon

In order to characterize the state of oil spill research and describe how the field has changed since its inception in the 1960s and since the Deepwater Horizon spill in 2010, we examined approximately 10% of oil spill literature (1255 of over 11,000 publications) published from 1968 to 2015. We find that, despite its episodic nature, oil spill research is a rapidly expanding field with a growth rate faster than that of science as a whole. There is a massive post-Deepwater Horizon shift of research attention to the Gulf of Mexico, from 2% of studies in 2004-2008 to 61% in 2014-2015, thus ranking Deepwater Horizon as the most studied oil spill. There is, however, a longstanding gap in research in that only 1% of studies deal with the effects of oil spills on human health. These results provide a better understanding of the current trends and gaps within the field.

Health effects of non-occupational exposure to oil extraction

Oil extraction may cause extensive environmental impact that can affect health of populations living in surrounding areas. Large populations are potentially exposed to oil extraction related contamination through residence in areas where oil extraction is conducted, especially in low and middle income countries (LMICs). Health effects among people residentially exposed to upstream oil industry contaminants have been poorly studied. Health effects of exposure to oil related contamination have been mainly studied among cleanup workers after oil spills from tankers or offshore platforms.In this paper we aim to identify the type and extension of residential exposures related to oil extraction activities and to comment on the few health studies available. We estimated that 638 million persons in LMICs inhabit rural areas close to conventional oil reservoirs. It is relevant to specifically study people residentially exposed to upstream oil industry for the following reasons: First, persons are exposed during long periods of time to oil related contamination. Second, routes of exposure differ between workers and people living close to oil fields, who can be exposed by ingestion of contaminated waters/foods and by dermal contact with contaminated water and/or land during daily activities (e.g. bathing, agricultural activities, etc.). Third, individuals potentially more susceptible to the effect of oil related contamination and not normally occupationally exposed, such as infants, children, pregnant women, elderly or people with previous health conditions, are also exposed.There are few papers studying the potential health effects of residential exposure to oil related contamination, and most of them share important limitations. There is a need for more research through the conduct of methodologically robust studies in exposed populations worldwide. Despite the difficulties in the conduct of studies in remote areas, novel approaches, such as measurement of individual exposure using biomarkers of exposure and effect, should be used. These studies should be promoted to understand the health risks associated to residential exposure to oil related contamination, support effective control policies to avoid such contamination and to sustain public health recommendations and policies to avoid exposure in already contaminated areas.

Health Risks Associated with Oil Pollution in the Niger Delta, Nigeria

Background: Although there is considerable public concern about the environmental impacts of oil pollution in the Niger Delta of Nigeria, actual evidence on the pathological and psychological effects in the health of local communities is minimally known. We sought to associate the perspective measures of exposure to oil pollution with health outcomes (inventory of health symptoms and functional capacity limitations) and determine how emotional reactions to environmental risks moderate these health outcomes. Method: The study was conducted with 600 participants selected from five local government areas in Akwa Ibom State where oil pollution is rampant. A structured questionnaire was used to collect the data on the respondents’ exposure to oil pollution, self-rated health and disease symptoms, perception of risk of exposure and emotional reactions to local oil pollution. Results: Most of the participants lived in areas with visible oil pollution and/or near gas flaring facilities and regularly suffered direct exposure to oil in their environment. High level of emotional distress was a part of everyone's life for the study population. Risk perception in the study area was mediated, to a large extent, by dreaded hazards (catastrophic fears of pipeline explosions and oil spill fire), visual cues (gas flares and smoke stacks) and chemosensory cues (off-flavor in drinking water). The exposure metrics were found to be significant predictors of the health effects and influencing factors (emotional reactions). Multi-levels models suggest that at the individual level, the demographic variables and direct contact with oil pollution were important mediators of functional capacity limitation. At the community level, emotional distress from fear of the sources of exposure was an important mediator of the health symptoms. Conclusions: This study documents high levels of disease symptoms and environmental distress (worry, annoyance and intolerance) associated with oil pollution in the Niger Delta areas of Nigeria. It highlights the need for some intervention to ameliorate the psychological distress associated with living under such environmental adversity.