Journal of Health and Pollution最新文献

Background: As resources become scarce, information from material and substance flow analysis can help to improve material recovery policy. The flow of toxic substances such as lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and antimony (Sb) can be used as a basis for appropriate risk management decisions for optimum environmental quality.

Objectives: The present study examined a material and substance flow analysis of used lead acid batteries (ULAB) from motor vehicles and implications for environmental quality in Nigeria.

Methods: Information on motor vehicle imports was obtained from the literature. Mathematical models were constructed and used for the material and substance flow analysis. Samples of 50 brands of ULAB pastes were digested using a microwave digestion system followed by elemental determination (Pb, Cd, silver (Ag), As, cobalt (Co), calcium (Ca), Cr, copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), Sb, selenium (Se), and tellurium (Te)) with inductively coupled plasma optical emission spectroscopy.

Results: Approximately 4.8 million tons (Mt) lead acid batteries (LAB) from vehicles was used in Nigeria between 1980 and 2014, out of which approximately 2.6 Mt had reached end-of-life (EoL) stages. From the total amount in EoL, approximately 2.3 Mt was recycled, and 0.3 Mt was landfilled. Among the toxic elements, Pb, Cd and As were the most abundant in ULAB; and of the valuable elements, Fe and Cu had the highest levels. Approximately 3.5 Mt of Pb was used in the past (1980-2014) in ULAB for motor vehicles, out of which approximately 1.9 Mt tons was in EoL stages.

Discussion: The results revealed that the battery pastes were heterogeneous. Only Pb exceeded the total threshold limit concentration (TTLC) of 1000 mg/kg. The TTLC describes the safe levels or concentration of heavy metals in the environment. The levels observed for other metals in this study were below the TTLC values. The present study estimated an average life span for lead acid batteries in motor vehicles in Nigeria of 5 years, suggesting an additional 2.2 Mt at EoL by 2019. High concentrations of Pb in air, water and soil carry the potential for contamination of food products, especially in Nigeria, where food is traditionally prepared and sold in open air markets in an unregulated manner.

Conclusions: High amounts of toxic elements present in the various life cycle stages signal potential environmental and human health hazards.

Competing interests: The authors declare no competing financial interests.

Background: Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals.

Objectives: The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar.

Methods: Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg.

Results: The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg^-1 for As, 3.070 mg.kg^-1 for Cd, 77.440 mg.kg^-1 for Hg, and 210.000 mg.kg^-1 for Pb.

Conclusions: The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines.

Competing interests: The authors declare no competing financial interests.

Background: Air pollution has become a major problem around the world and is increasingly an issue in Togo due to increased vehicular traffic. Gaseous pollutants are released by engines and are very harmful to human health and the environment. The fuels used on the major road in Togo, the N2, are adulterated with unknown contents and are of poor quality. Many of the vehicles come from neighboring countries, such as Benin, Ghana and Nigeria.

Objectives: The present study aims to evaluate the pollution rate in Togo through the estimation of the concentrations of sulfur dioxide (SO₂), nitrogen oxides (NO_x), and particular matter (PM) on the international road, the National Road N2, in Lomé, compared to the World Health Organization's (WHO) standard limit.

Methods: The simulations of pollutant concentration were performed using the Industrial Source Complex Short Term Version 3 model, which is included in the United States Environmental Protection Agency Regulatory Model (USEPA) AERMOD View software. The meteorological averages data were obtained from the local station near the National Road N2 in Togo in 2018. Hourly averages were calculated according to the European Monitoring Evaluation Programme/European Environmental Agency air pollutant emission inventory guidebook 2016 and were processed using AERMET View and a terrain pre-processor, AERMAP. For the model, the sources of pollution were the vehicles traveling on the road segment. The source was a line volume with 20 m of width and 2 m of height. The estimation methodology covered exhaust emissions of NO_x, SO₂ and PM contained in the fuel.

Results: The simulations provided average hourly, daily and annual concentrations of the different pollutants: 71.91 μg/m³, 42.41 μg/m³,11.23 μg/m³ for SO₂; 16.78 μg/m³, 9.89 μg/m³, 2.46 μg/m³ for NO_x and below the detection limit, 0.62 μg/m³, 0.15 μg/m³ for PM, respectively. These results indicate that on the National Road N2 in Togo, the concentrations of SO₂ were high compared to those of NO_x and PM. The daily average concentration of SO₂ was twice the permissible limits set by the WHO.

Conclusions: Emissions obtained from the AERMOD for NO_x and PM were less than the permissible limits set by the WHO, while the rate of SO₂ was twice the permissible limit. The fuels used on this road were very rich in sulfur. The sulfur level in fuels must be monitored by stakeholders in Togo.

Competing interests: The authors declare no competing financial interests.

Background: Air pollution poses a significant threat to human health worldwide. Investigating potential health impacts is essential to the development of regulations and legislation to minimize health risks.

Objectives: The aim of the present study was to investigate the potentially hazardous effect of air pollution on the Ali Sabah Al Salem residential area in Kuwait by comparing the pollution level to a control area (Al-Qirawan) by assessing two biomarkers: erythrocyte glutathione S-transferases (e-GST) and total blood antioxidant, and then correlating the activity to pollution-related oxidative stress.

Methods: The average concentrations of several airborne gases were measured at Ali Sabah Al Salem and Al-Qirawan, including ozone, carbon monoxide, nitrogen dioxide, nitrogen oxides, particulate matter less than 10 μm (PM₁₀), sulfur dioxide, ammonia, carbon dioxide, hydrogen sulfide, methane, and non-methane hydrocarbon. A total of fifty-eight participants were sampled from two different areas and divided into two groups. The study group was composed of 40 residents exposed to polluted ambient air in the Ali Sabah Al Salem residential area. A reference group composed of 18 residents in the Al-Qairawan area living far from major pollution sources was also tested.

Results: All measured gases were higher in concentration at Ali Sabah Al Salem compared to the Al-Qirawan area. Furthermore, PM₁₀ and sulfur dioxide were higher than World Health Organization (WHO) guidelines. The e-GST activity was lower among participants of the Ali Sabah Al Salem residential area compared to participants living in the Al-Qairawan area. The total antioxidant capacity in whole blood of Ali Sabah Al Salem residents was significantly (p<0.0001) higher than in control subjects.

Conclusions: Residents in Ali Sabah Al Salem are exposed to a high level of air pollution that has a serious impact on glutathione S-transferases levels. Subsequently, regulations on pollution sources are needed to lower current health risks. Furthermore, the present study provides evidence that finger-prick blood sampling is a quick, non-invasive method suitable for screening e-GST activity and total antioxidants which may be applied for surveillance purposes.

Participant consent: Obtained.

Ethics approval: The study was approved by the Scientific Research Committee of the Public Authority for Applied Education and Training, Kuwait.

Competing interests: The authors declare no competing financial interests.

Background: Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which serve as repositories and as sources of contamination of other habitats.

Objectives: The present study assessed temporal changes in the pH, particle size and concentration of metals in sediments of a mining-affected river in Zambales, Philippines.

Methods: Sediment samples were collected at different periods in four stations along the river using a modified Van Veen grab. The samples were subjected to quartering, air-drying, and sieved through a mesh of 40 mm prior to X-ray fluorescence spectroscopy analysis using Thermo Scientific Niton XL3t to determine metal concentrations. The sediment particle size was analyzed by the sieve method and soil pH by the electrode method.

Results: Measured metal concentrations in the sediment were as follows: iron (Fe)> calcium (Ca)> chromium (Cr)> nickel (Ni)> manganese (Mn) with averages of 174.6 mg/g, 7.89 mg/g, 6.54 mg/g, 4.82 mg/g, and 2.75 mg/g dry matter (DM), respectively. The mean pH of riverine sediments was generally neutral, except for Station 4. In terms of particle size, silt and clay fractions increased in the upstream station but decreased in the midstream and downstream stations across the sampling periods. The flooding brought by Typhoon Koppu resulted in lowered concentrations of Fe, Mn, Cr, and Ni and an upsurge in Ca and potassium levels.

Discussion: Most of the heavy metals (Fe, Ni, Cr, Mn) exceeded the probable effect level (PEL) for inorganics in sediments, suggesting that the adverse effects of these metals on the environment and aquatic organisms are expected to occur frequently. In comparison with Station 4, which was less affected by siltation, there was a sign of metal enrichment in the area. This indicates that soil erosion and runoff, which might have been triggered by vegetation loss, mineral extraction, and agricultural activities, had a significant impact on the quality of river sediments.

Conclusions: The findings of the study point to the need for the formulation and implementation of appropriate regulatory measures for the protection and rehabilitation of the heavy metal-loaded river.

Competing interests: The authors declare no competing financial interests.

Background: Hazardous material (HAZMAT) transportation drivers are responsible for safe delivery of consignments and face multiple challenges carrying out their duties. Drivers are also the first to respond to emergencies and accidents.

Objectives: The purpose of the present study was to identify the essential competencies needed by HAZMAT transportation drivers to deal with emergencies.

Methods: Three rounds of focus groups were conducted using expert panels comprised of HAZMAT specialists, health, safety and emergency representatives, security experts and transportation advisors from June to July 2019. The panel discussed competencies, gathered from a literature review, for emergency responders.

Results: The panel identified six (6) core and 23 sub-competencies of HAZMAT drivers. This is the first study in low- and middle-income countries (LMIC) to identify core competencies of HAZMAT truck drivers.

Conclusions: The integration of these competencies into a development and training program for drivers will better enable drivers to handle emergencies in an efficient and effective manner.

Participant consent: Obtained.

Ethics approval: The Graduate Advisory Committee of Comsats University approved study protocols.

Participant consent: Obtained.

Competing interests: The authors declare no competing financial interests.

Background: In recent years, poor urban air quality in Delhi, India has gained significant attention. Episodic events including crop stubble burning and Diwali celebrations are considered major factors in the worsening quality of ambient air.

Objective: This study aimed to investigate spatial and monthly variation as well as the role of episodic events in ambient air quality in Delhi, including the 'Great Smog' month of November 2017.

Methods: Monitoring of air pollutants (particulate matter (PM₁₀, PM_2.5, PM₁) and nitrogen dioxide (NO₂)) was carried out at three distinct locations of Delhi from April 2017-February 2018. The concentration of NO₂ was measured using a modified Jacob and Hochheiser method and PM was measured using a GRIMM aerosol spectrometer. Air quality index was also determined to identify the effects of air pollution on human health.

Results: Overall, the levels of air pollution were found to be approximately 2.1-3.2 times higher along a traffic intersection and about 1.4-2.0 times higher in a commercial area compared with an institutional area. The highest average monthly concentrations of PM₁₀, PM_2.5, PM₁ and NO₂ were 768, 374, 298 and 149 μg/m₃, respectively, during the Great Smog month of November 2017. November and August were recorded as the most polluted and cleanest months, respectively, in the city. Generally, poor to severe categories of the air quality index (AQI) were obtained from October to February. Higher concentrations during November were attributed to stubble burning in the nearby states of Delhi with the additive effect of fireworks during Diwali celebrations.

Conclusions: Severe ambient air quality as observed in the present study is a serious matter of concern for the health of Delhi's population. To control spikes in poor air quality during episodic events, it is imperative to raise awareness among farmers regarding the severe health hazards of stubble burning.

Competing interests: The authors declare no competing financial interests.

Background: The respiratory system of children is vulnerable to exposure to particulate matter (PM) with a diameter of less than 2.5 and 10 μm (PM_2.5 and PM₁₀) or even lower.

Objective: This study assessed PM₁₀ and PM_2.5 levels and respiratory health impacts on children in schools located in an industrialized suburb in Kenya.

Method: The PM₁₀ and PM_2.5 levels were sampled from five public primary schools in Athi River Township and a control school during the wet and dry seasons. Outdoor and classroom samples were collected concurrently on an 8-hour mean during school hours on two consecutive days in each school and analyzed using gravimetric techniques. Five hundred and seventy-eight (n = 578) pupils aged 9-14 years from these schools were also evaluated for symptoms of respiratory illnesses and lung function using a questionnaire and spirometric method, respectively, during the same periods.

Results: Indoor median PM₁₀ levels (μg/m³) ranged from 60.8-269.1 and 52.8-232.3 and PM_2.5 values (μg/m³) of 17.7-52.4 and 28.5-75.5 during the dry and wet seasons, respectively. The control classrooms had significantly (p <0.05) lower median PM₁₀ levels (μg/m³) of 5.2 and 4.2, and PM_2.5 levels (μg/m³) of 3.5 and 3.0 during the respective seasons. Nearly all the classrooms in Athi River schools had PM_2.5 and PM₁₀ median levels that exceeded the World Health Organization (WHO) recommended levels. The indoor-to-outdoor ratios varied from 0.35-1.40 and 0.80-2.40 for PM₁₀ and 0.30-0.80 and 0.80-1.40 for PM_2.5 during the dry and wet seasons, respectively, suggesting higher levels in the classrooms during the wet season. The relative risk (RR) and odds ratio (OR) presented higher prevalence of respiratory diseases following PM exposure in all the Athi River schools than the control during the dry and wet seasons. At 95% CI, the RR and OR showed strong associations between high PM₁₀ and PM_2.5 levels and lung function deficits and vice versa. The association was more prevalent during the wet season.

Conclusions: The study calls for effective indoor air management programs in school environments to reduce PM exposure and respiratory health impacts.

Participant consent: Obtained.

Ethics approval: The research permit and approvals were obtained from the University of Nairobi/Kenyatta National Hospital Ethics and Research Committee (KNH-UoN ERC Reference: P599/08/2016) and the National Commission for Science, Technology and Innovation (Reference: NACOSTI/P/18/4268/25724).

Competing interests: The authors declare no competing financial interests.

Background: Mining, waste disposal, and agrochemical residues have contributed to pollution of water and soil with toxic metals in most low- and middle-income countries, raising concerns of ecological safety and public health. This has prompted many studies into the production and utilization of biochars to adsorb toxic metal contaminants from soil and water.

Objective: The present study presents a review of biochar properties, the mechanisms of toxic metal adsorption onto biochar, and sorption of toxic metal contaminants in water and soil in small scale applications and laboratory experiments.

Methods: A total of 305 articles were collected, and after screening for relevance, a final of 164 articles from both high- and low- and middle-income countries were used in this review paper.

Discussion: Biochar for sorption has proven effective and its raw materials are readily available, cost effective, environmentally stable and a good form of waste management.

Conclusions: Different techniques of biochar production influence the properties of biochar and adsorption of toxic metals from water and soil.

Competing interests: The authors declare no competing financial interests.