Background: Wood, a common fueling material for fish smoking in Nigeria, contains polycyclic aromatic hydrocarbons (PAHs) which have been found to be carcinogenic and pose a human health hazard.
Objectives: The present study investigated the interactions and effects of kiln types on levels of PAHs in smoked fish.
Methods: Twenty fresh samples of Clarias gariepinus with an average size of 800 g were eviscerated, washed and salted for smoking. Sixteen (16) of the fish were randomly and equally allotted to each of the two kilns (treatments) and replicated three times in a completely randomized design. Each kiln was loaded and heated up with hard wood charcoal and the effects were evaluated on the resulting smoked fish. The remaining four fish samples were kept under refrigeration (controls). Samples of the smoke-dried fish from each kiln were homogenized using a porcelain mortar and pestle, sieved through a 250-μm2 sieve, and packaged in labeled airtight containers prior to extraction. Pure extracts from the samples were subjected to gas chromatography.
Results: The results showed that the PAH concentration in non-smoked catfish was 1.0 mg/kg, the PAH concentration in fish samples smoked with a traditional kiln was 2.0 mg/kg, and no PAHs were detected in samples smoked with a mechanical kiln.
Conclusions: The level of PAH contamination of smoked fish is dependent on the type of kiln used, as demonstrated by the differences between fished smoked with traditional and mechanical kilns in the present study.
Competing interests: The authors declare no competing financial interests.
Background: Artisanal and small-scale gold mining (ASGM) is one of the largest sources of mercury (Hg) pollution in Indonesia. In West Java Province, ASGM is found in Bogor, Cianjur, and Sukabumi Regencies.
Objectives: The present study aimed to evaluate Hg contamination effects and socioeconomic factors in communities living around ASGM operations in Sukabumi Regency.
Methods: A quantitative method was used to describe socioeconomic ASGM communities. The concentrations of total mercury (T-Hg) in hair were measured in 71 respondents. This study also assessed perception of the use of Hg in the gold ore processing and their impact on the environment.
Results: The population of gold miners in the studied three villages was 1300 households (25.77% from a total of 5044 households). Artisanal and small-scale gold mining involves both men and women employed as miners and gold amalgam processors, respectively. The average monthly income generated as much as Indonesian Rupiah (IDR) 272 000-2 000 000 (about 19-140 USD). Total Hg analysis was conducted for hair samples of 71 respondents (38 men, 33 women). The results showed an average T-Hg in men of 3.27±2.89 ppm, and women of 5.91±4.69 ppm. The level of T-Hg in the respondents was associated with distance to the ball mills and not related to distance to the mine site.
Participant consent: Obtained.
Ethics approval: This study was approved by Ministry of Environment and Forestry of the Republic of Indonesia.
Competing interests: The authors declare no competing financial interests.
Background: As water flows through habitats associated with estuaries, such as mud flats, salt marshes, sea grass and mangrove forests, pollutants such as heavy metals are filtered. The fine sediment dominant in intertidal and subtidal estuarine systems is an important sink for these contaminants. Periwinkle, which inhabit estuarine ecosystems, are known to bioaccumulate large quantities of contaminants.
Objectives: In view of the widespread consumption of periwinkle in the Niger Delta, Nigeria, this study was designed to assess the concentration and potential human health hazards of heavy metals due to the consumption of this rich, inexpensive and readily available source of protein in Calabar, Nigeria.
Methods: Lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni) content of edible tissues of periwinkles obtained from major markets in Calabar were determined using Shimadzu atomic absorption spectrophotometer (Model AA-6800, Japan) after wet digestion.
Results: The ranges of concentration (mg/kg dry weight) were Pb (0.011-0.056), Cd (0.008-0.032), Cr (0.014-0.157) and Ni (0.053-0.261) for Watt Market and Pb (0.009-0.052), Cd (0.011-0.032), Cr (0.012-0.052) and Ni (0.012-0.322) for Mariam Market. Concentrations of all the metals were below Food and Agricultural Organization (FAO), FAO/World Health Organization (WHO) and Commission of European Communities maximum permissible limits. The estimated daily intake (EDI) of Pb and Cd were slightly higher compared to the recommended daily intake for the metals. The EDI of all metals under study were lower than the upper tolerable daily intake. The target hazard quotients (THQ) computed to estimate the human health risk posed by each metal were above the safe limits of unity, except for Cr. The hazard index (HI) for a typical adult of 60.7 kg body weight was found to be 9.7 for Watt Market and the relative contributions to the aggregated risk were 24.66%, 54.51%, 0.0001% and 20.70% for Pb, Cd, Cr and Ni, respectively. The HI for Marian Market was 10.7 and the relative contributions to the aggregated risk were 22.31%, 57.55%, 0.06% and 20.09% for Pb, Cd, Cr and Ni, respectively.
Conclusions: Consumption of periwinkles purchased from major markets in Calabar poses toxicological risk with respect to Pb, Cd and Ni poisoning.
Competing interests: The authors declare no competing financial interests.
Background: Automobile spray painters in Nigeria are exposed to organic solvents due to the hazardous nature of their work. Inadequate use of personal protective equipment (PPE) may intensify exposure to high levels of chemical hazards with resultant health problems.
Objectives: The present study assessed PPE use and work practices and compared work-related health problems of spray painters and controls in Ile-Ife, Nigeria.
Methods: A cross-sectional study was conducted among 120 spray painters and 120 controls (electronic technicians). Data on socio-demographics, work practices, knowledge about organic solvent-related hazards and self-reported health symptoms were obtained using a semi-structured questionnaire. Clinical examinations were performed for all respondents and the composition of organic solvents in paints and paint products were derived from material safety data sheets.
Results: All respondents were male, and the mean age was 32.7±13.8 years for painters and 33.9±15.5 years for controls. Few (7.5%) painters perceived their use of PPE to be adequate. All spray painters worked in enclosed workshops and N-butyl acetate was the most commonly used organic solvent. Spray painters reported excessive tear production, recurrent cough, and short-term memory loss more frequently than controls (P<0.05). In addition, 89% of painters noticed paint-stained sputum immediately after spray painting. The prevalence ratio of respiratory symptoms was higher in spray painters than controls (prevalence ratio=21.0, CI=2.9-153.6). On clinical examination, more spray painters had corneal opacity and dry skin when compared with controls (P<0.05).
Conclusions: Spray painters in the study area worked amidst chemical hazards and had poor use of PPE. Exposure to organic solvents may be responsible for the higher prevalence of self-reported health problems among spray painters. Interventions to enforce the use of PPE and improve the knowledge of organic solvent-related hazards among spray painters are essential.
Participant consent: Obtained.
Ethics approval: Ethical approval to conduct the study was obtained from the Health Research and Ethics Committee of the Institute of Public Health, Obafemi Awolowo University, Ile-Ife Nigeria (HREC No: IPHOAU/12/463).
Competing interests: The authors declare no competing financial interests.
Background: Rivers are susceptible to pollution and water pollution is a growing problem in low- and middle-income countries (LMIC) with rapid development and minimal environmental protections. There are universal pollutant threshold values, but they are not directly linked to river activities such as sand mining and aquaculture. Water quality modelling can support assessments of river pollution and provide information on this important environmental issue.
Objectives: The objective of the present study was to demonstrate water quality modelling methodology in reviewing existing policies for Malaysian river catchments based on an example case study.
Methods: The MIKE 11 software developed by the Danish Hydraulic Institute was used to model the main pollutant point sources within the study area - sand mining and aquaculture. Water quality data were obtained for six river stations from 2000 to 2015. All sand mining and aquaculture locations and approximate production capacities were quantified by ground survey. Modelling of the sand washing effluents was undertaken with the advection-dispersion module due to the nature of the fine sediment. Modelling of the fates of aquaculture deposits required both advection-dispersion and Danish Hydraulic Institute ECO Lab modules to simulate the detailed interactions between water quality determinants.
Results: According to the Malaysian standard, biochemical oxygen command (BOD) and ammonium (NH4) parameters fell under Class IV at most of the river reaches, while the dissolved oxygen (DO) parameter varied between Classes II to IV. Total suspended solids (TSS) fell within Classes IV to V along the mid river reaches of the catchment.
Discussion: Comparison between corresponding constituents and locations showed that the water quality model reproduced the long-term duration exceedance for the main body of the curves. However, the water quality model underestimated the infrequent high concentration observations. A standard effluent disposal was proposed for the development of legislation and regulations by authorities in the district that could be replicated for other similar catchments.
Conclusions: Modelling pollutants enables observation of trends over the years and the percentage of time a certain class is exceeded for each individual pollutant. The catchment did not meet Class II requirements and may not be able to reach Class I without extensive improvements in the quality and reducing the quantity of both point and non-point effluent sources within the catchment.
Competing interests: The authors declare no competing financial interests.
Background: Since March 2020, the number of confirmed COVID-19 positive cases have steadily risen in India. Various preventive measures have been taken to contain the spread of COVID-19. With restrictions on human activities, anthropogenic emissions driving air pollution levels have seen a reduction since March 23, 2020, when the government imposed the first nationwide shutdown. The landlocked Indo-Gangetic Plain (IGP) has many densely-populated cities, witnessing high levels of particulate matter due to both nature-driven and anthropogenic elements. Kanpur is an urban metropolis in the IGP with high aerosol loading, and this paper explores the impact of restricted anthropogenic activities on aerosol characteristics in Kanpur.
Objectives: This study aims to investigate the change in aerosol optical depth level and its related parameters during the shutdown phases in Kanpur city compared to the same time periods in 2017-2019.
Methods: Aerosol optical properties such as aerosol optical depth (AOD) at 500 nm, Angstrom exponent (AE), fine mode fraction (FMF) of AOD at 500 nm and single scattering albedo (SSA) at 440 nm were obtained from the Aerosol Robotic Network (AERONET) station operating in Kanpur from the 1st March to the 30th April for 2017-2020.
Results: A significant decrease in aerosol loading was observed during the shutdown period compared to the pre-and partial shutdown periods in 2020 as well as during the same time periods of 2017-2019. Mean AOD, FMF and SSA were 0.37, 0.43 and 0.89, respectively, during the shutdown period in 2020. A 20-35% reduction in mean AOD levels was observed during the shutdown period in 2020 as compared to the same period in 2017-2019.
Conclusions: The shutdown led to an improvement in air quality due to decreases in anthropogenic emissions. As fine particles, typically from urban and industrial emissions, dominate episodic air pollution events, this study can be further utilized by the scientific community and regulators to strengthen the emergency response action plan to check high pollution episodes in Kanpur city until cleaner technologies are in place.
Competing interests: The authors declare no completing financial interests.
Background: Cowpea is a leguminous crop commonly grown and eaten in Nigeria. Organophosphate insecticides are frequently used to control insect populations in cowpea crops.
Objectives: The present study was conducted to investigate the concentrations of organophosphate insecticide residues in cowpea varieties in Gwagwalada, Nigeria, and assess health risks to consumers.
Methods: Samples of brown and white cowpea varieties were collected from Gwagwalada market, Abuja, Nigeria. Concentrations of organophosphate insecticide residues in the cowpea samples were analyzed by gas chromatography-mass spectrometry with selective ion monitoring. Risk evaluation was carried out by the determination of estimated daily intake, hazard quotient and chronic hazard index.
Results: The organophosphates detected in the cowpea varieties were malathion, parathion, ethion and carbophenothion. The concentrations of insecticides in the cowpea types were higher than the maximum residue limits recommended by the European Union (EU) and the Agency for Toxic Substances and Disease Registry (ATSDR). The hazard quotient values were less than 100% for malathion, parathion and ethion in the cowpea varieties for adults and children. The hazard quotient of carbophenothion for adults was below 100% for the cowpea types, while the hazard quotient surpassed 100% for children. The chronic hazard indexes for children were 364% and 276% for the brown and white cowpea types, respectively.
Conclusions: The results obtained in the present study indicate that consumers, particularly children, may be exposed to health risks through the consumption of cowpea types. Consequently, monitoring and regulation of organophosphate insecticide usage in Nigeria should be intensified.
Background: Many developing countries either lack or have weakly enforced regulations on imported goods. A high percentage of low-cost jewelry items in Nigeria are imported from abroad. There is concern about the levels of heavy metals present in these products.
Objectives: The present study examined the levels of lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni) in inexpensive jewelry purchased from retail wholesale shops in Ibadan metropolis, southwestern Nigeria.
Methods: One hundred (100) assorted jewelry items were digested in dilute nitric acid solution followed by atomic absorption spectrophotometric analysis.
Results: Out of the total number of jewelry items analyzed, 12% of them had Pb concentrations above European Union (EU) safety limits. Also, 63%, 42% and 62% of items had Cd, Cr and Ni average concentrations above their EU limits. Notably, 3%, 27% and 8% of the items had Pb, Cd and Cr concentrations over 103 times above their EU limits Overall, Cd showed the highest average level in rings (256,952 mg/kg) followed by bracelets (60,627 mg/kg) and earrings (54,388 mg/kg). All metals in solid bangles were within their EU guidelines.
Conclusions: Given the significant deleterious impacts of these metals on human health, low-cost jewelry poses a serious potential threat to users' health. Policies to guarantee the safety of low-cost jewelry items must be established and enforced.
Competing interests: The authors declare no competing financial interests.
Background: Airborne particulates are an issue in many urban regions around the world and their detrimental impact on human health has increasingly become a public health concern.
Objectives: The aim of the present study was to examine particle pollution in an urban settlement in Nigeria. This study examines the extent, spatial variation, and sources of indoor and outdoor particulate matter (PM) concentrations in Ogbomoso, Nigeria.
Methods: The survey research method was adopted. Sampling included 385 buildings across selected precincts and different residential zones in the town of Ogbomoso. Particulate matter analytes (PM1, PM2.5 and PM10) within/around each building were measured with a particle counter and details on domestic utilities/practices were obtained with a questionnaire. Analysis of variance was used to determine inter-zonal variations in PM levels and simple linear regression was used to analyze the relationship between indoor and outdoor air quality.
Results: Indoor and outdoor respirable particle (PM2.5) concentrations were lower than the World Health Organization (WHO) Interim Target limit of 75 μg/m3, while concentrations of inhalable particles (PM10) were higher than the set limit of 150 μg/m3 for daily averages. Coarse particles dominated, with an accumulative PM2.5/PM10 ratio of 0.24. The inter-zonal analysis of PM concentrations revealed that indoor and outdoor PM levels varied significantly by residential zone (p = 0.0005; p = 0.01, respectively). Regression analysis showed a significant but weak relationship between indoor and outdoor PM levels (r = +0.221), while the coefficient of determination (R2 = 0.049) showed that only about 5% of the variation in indoor air quality was associated with outdoor air quality. Particle pollution inducers were identified in the residents' waste disposal methods and adopted fuels/energy sources, with firewood and charcoal linked with increased concentrations of particulate matter.
Conclusions: Air quality was relatively poor in the study area given observed particulate matter concentrations. Cleaner fuels, effective waste management systems and improved roads are needed to foster better air quality in the study area.
Competing interests: The authors declare no competing financial interests.
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