Potential Health Risk Assessment Research Articles

Potential health risk assessment, spatio-temporal hydrochemistry and groundwater quality of Yamuna river basin, Northern India

Groundwater which is an essential source of freshwater for various domestic, agricultural, industrial applications is facing a severe deterioration in quality due to demographic pressure and intense industrial activities. Present study appraises the influence of human induced activities on groundwater quality of Agra-Firozabad industrial belts of Western Uttar Pradesh, Yamuna basin, India. The maximum concentrations of metals and anions found during pre and post monsoon are as follows: Lead 0.302; 0.086, calcium 672; 1260, magnesium 215; 16.8, cadmium 0.0; 0.066, chromium 0.016; 0.005, manganese 0.340; 0.076, nickel 0.044; 0.028, sulfate 514; 286, nitrate 66.7; 3.56 and fluoride 1.17; 2.02 mg/L respectively. Based on results of Water Quality Index, groundwater samples were classified under ‘Poor water’ category in 34.2% and 52.63% during pre and post-monsoon period, respectively. Accordingly, higher concentrations of bicarbonate and sulfate might have attributed to excess hardness, instrumental in making it unsuitable for industrial usage. However, values of Percent Sodium, Sodium Adsorption Ratio, Magnesium Hazard and Permeability Index signified that groundwater from majority of locations was fit for agricultural use. Health risk assessment studies revealed that children consuming polluted water were affected more as compared to adults. Timely action and strict compliance of regulation is recommended towards groundwater management for defined usage to avert severe health effects and to meet sustainable development goals.

Pesticide residues in corn and soil of corn fields of Khuzestan, Iran, and potential health risk assessment

Corn is the second most plentiful cereal grown for human consumption. Corn has several pests and diseases and various kind of pesticides are used for controlling these, and reducing their damage. In this study, 49 pesticide residues in 34 corn samples and nine corn field soil samples collected from eight cities of Khuzestan province as the main agricultural products in Iran were analyzed using a miniaturized QuEChERS extraction method. In addition, non-carcinogen and carcinogen health risk assessments were evaluated. Indoxacarb, metribuzin, propamocarb, and thiabendazole residues were detected in some corn samples. In addition, atrazine, cymoxanil, and propamocarb residues were found in some corn field soil samples. Results indicated that 35% of corn samples had at least one pesticide, of course, less than the maximum residue limit (MRL), except thiabendazole in 12 samples includes residue more than the acceptable limit. In addition, the Hazard index (HI) of corn samples was 1.83 × 10−4 and 8.53 × 10−4 in adults and children, respectively. No significant carcinogenic risk threatens corn consumers.

Ecological risk and health risk analysis of soil potentially toxic elements from oil production plants in central China

In this study, the enrichment factor (EF) and pollution load index (PLI) were used to evaluate the pollution of potential toxic elements (PTEs) in the soil near the oil production plants in central China, and the potential ecological risk (PER) and human health risk (HHR) assessment model were used to evaluate the PER and HHR caused by the soil PTEs in the study area. The mean EFs of all PTEs were greater than 1, PTEs have accumulated to varying degrees, especially Cr, Ni and Pb were the most serious. The average value of PLI was 2.62, indicating that the soil PTEs were seriously polluted. The average {E}_{r}^{i} values of PTEs were Cr > Pb > Cd > Ni > As > Cu > Zn > Mn, of which Cr, Pb, Cd and Ni were at medium and above PER levels. Both adults and children in the study area suffered from varying degrees of non-carcinogenic and carcinogenic risks. The total hazard index (THI) values of children (7.31) and adults (1.03) were all > 1, and the total carcinogenic risk index (TCRI) of children (9.44E−04) and adults (5.75E−04) were also > 10–4. In particular, the hazardous quotient (HQ) of Cr and Pb for children under the oral intake route were 4.91 and 1.17, respectively, caused serious non-carcinogenic risk. And the carcinogenic risk index (CRI) values of the PTEs in adults and children under the three exposure routes were Cr > Ni > > As > Pb > > Cd. Among them, the CRI values of Cr and Ni in children and adults by oral intake were both greater than 10–4, showing a strong carcinogenic risk. The results will provide scientific basis for environmental protection and population health protection in this area.

Potential environmental pollution and human health risk assessment due to leachate contamination of groundwater from anthropogenic impacted site

One of the consequences of landfill systems is the emission of leachate, which is capable of causing contamination of the surrounding environment, including groundwater. Considering three major abandoned landfills in an urban area in Nigeria, the potential environmental pollution due to leachate generated from landfills and human health risk assessment of nearby groundwater were examined using laboratory standards (APHA 2012). The result revealed that the landfills' leachate pollution index (LPI) is 18.84, 19.57, and 19.66, indicating potential pollution of the environment, including groundwater and soil. Conformity of groundwater indicated that Arsenic (Ar-0.0001), Cadmium (Cd-0.002), Zinc (Zn-0.02), Barium (Ba-0.03), Manganese (Mn-0.05), Copper (Cu-0.02, 0.012), Chromium (Cr-0.006, 0.007), and Cobalt (Co-0.03, 0.015) are within the WHO permissible limit while Nickel (Ni-0.06) and Lead (Pb-0.05) exceeded the permissible limit. Using the USEPA model for human health risk assessment, the Total Hazard quotient (THQ) for ingestion and derma exposure indicated that the heavy metals have ≤1 across the three landfills, indicating that the exposed population experience no significant health risk. The THQ trended as Cd>Co>Zn>Ba>Mn>Cu>Cr>Ni>As>Pb for children across all the landfills. The estimation for Total Carcinogenic Risk (TCR) for carcinogenic metals (As, Cd, Cr, Ni, and Pb) from various landfill indicated no carcinogenic risk (TCR <10−6). Although the abandoned landfills showed potential environmental pollution and contamination of groundwater; however, the health risk assessment of the groundwater revealed no significant carcinogenic risk to the population exposed to it. Hence, the need for water treatment and evaluation of the soil contamination status of landfills.

Evaluation of Heavy Metals in Vegetables from Contaminated Agricultural Soils of Madhyapur Thimi, Bhaktapur District, Nepal and their Potential Health Risk Assessment

The present study aimed to determine Cd, Cr, Cu, Pb, and Zn concentrations using flame atomic absorption spectrophotometer (FAAS) in five vegetables viz., Coriander (Coriandrum sativum), Mustard (Brassica campestris), Radish (Raphanus sativus), Spinach (Spinacea oleracea) and Chinese spinach (Amaranthus dubius), and their growing soils in three agricultural sites (Manohara, Bode, and Nagadesh) of Madhyapur Thimi, Bhaktapur district and to assess health risks using USEPA deterministic approaches. The average concentrations of HMs in soils were 0.85, 30.65, 40.06, 47.42, and 129.55 mg/kg for Cd, Cr, Cu, Pb, and Zn respectively, exceeding the normal soil quality standards except Cr. Similarly, the average concentrations of HMs in vegetables were 0.42, 6.63, 22.33, 1.34, and 77.16 mg/kg for Cd, Cr, Cu, Pb, and Zn respectively exceeding joint FAO/WHO standards except for Cu. The I-geo values revealed a class of unpolluted to moderately polluted levels for the agricultural soils indicating the 1st degree of soil pollution. Among the vegetables, Chinese spinach measured considerably high transfer factor (TF) for Cd (0.79), Cr (0.34), Cu (0.76), Pb (0.04), and Zn (0.89) indicating health concerns to the consumers. The hazard index (HI) for these HMs was found less than the acceptable limit (1.0) indicating no non-carcinogenic risk to adults through vegetable consumption. However, the lifetime carcinogenic risk (LCR) parameter indicated low to high cancer risk for Cd, Cr, and Pb. Among the vegetables, Chinese spinach estimated the highest LCR values for the HMs suggesting regular monitoring of HMs in soil and vegetable on account of their toxic effects.

Modeling of Inhalation Health Risk of Volatile Organic Compounds in the Vicinity of Maptaphut Petroleum and Petrochemical Industrial Estate, Thailand

The purpose of this research was to explicate a human health risk assessment that can be employed with inhalation risk estimates to provide a screening level of risks. Model input parameters provide reasonable values with the site- and compound-specific values relied on by the Human Health Risk Assessment Protocol (HHRAP). This method uses a generic risk assessment, consisting of air dispersion and deposition modeling followed by risk modeling. An intensive evaluation was conducted in the surrounding area of the largest petroleum and petrochemical estate in Thailand, the Maptaphut industrial area, where a large volume of VOCs was emitted, with an increasing negative health impact on the local population. The potential inhalation health risk assessment showed that the lifetime cancer risk in all residential areas is higher than the health benchmarks. The highest cancer risk was 7.82 × 10−2 in children and 3.91 × 10−1 in adults. The inhalation effects are based on the specific emission rates, the united concentrations and deposition fluxes, and the emission phase. The results revealed that four VOCs (benzene, 1,3-butadiene, vinyl chloride, and 1,2-dichloroethane) should be given priority when controlling for sustainable health risk management through the comprehensive analysis of the integrated analysis of air dispersion and health risk mathematical models.

Distribution Characteristics and Risk Assessment of Antimony in Typical Urban Soil

In order to study the distribution characteristics and potential risk of antimony (Sb) in urban soil, the concentrations of soil Sb in four different land use types were analyzed based on the data of 1670 soil samples with different vertical profiles in 102 plots in Shanghai. The risks were evaluated using the potential ecological risk index method and health risk assessment model. The results showed that the average ω(Sb) in the study area was 0.52 mg·kg-1, and the content of soil Sb gradually declined with the rise in soil profile depth. Sb was enriched in surface soil, which indicated that human activities had caused disturbance to the distribution of Sb in the soil. The content of Sb in the surface soil of industrial land was higher than that of residential land and commercial land, and the content of Sb in agricultural land was the lowest. The single-factor pollution index of industrial land was the highest, reaching a slight pollution level, whereas the residential land, commercial land, and agricultural land were at even-clean or clean levels, respectively. The whole region showed slight ecological risk, with the potential ecological risk index ranging from 4.23 to 7.61. The potential ecological risk level of industrial land was moderate, which needs to be addressed. The results of health risk assessment showed that the non-carcinogenic risk of Sb in the soil was low; however, it is of great concern to residents, especially children, when on residential land.

Trace heavy metals and harmful elements in roots and rhizomes of herbs: Screening level analysis and health risk assessment

ObjectiveHeavy metal and harmful element contamination are frequently reported in Chinese herbal medicines (CHMs), and roots and rhizomes parts showed a higher content than other parts. To investigate the residue level and assess the potential human health risk of heavy metals and harmful elements in roots and rhizomes, 720 batches of the sample representing 20 species of herbs from different sources were collected. MethodsThe content of Pb, Cd, As, Hg, and Cu in the digests was determined using ICP-MS. The chronic hazard index estimate based on non-cancer hazard quotient (HQ) was applied for potential health risk assessment of Pb, Cd, As, Hg, and Cu via consumption of CHMs. ResultsCompared with the Chinese limit standard (Chinese Pharmacopoeia Commission, 2020 edition) of Pb, Cd, As, Hg, and Cu in Ginseng Radix et Rhizoma, the exceedance percentage of Pb in total samples was 14.1%, which were generally far higher than Cd, As, Hg, and Cu. Health risk assessment results based on hazard quotient calculating showed that total HQ of Cu, Pb, As, Cd, and Hg in Pulsatillae Radix and Clematidis Radix et Rhizoma exceeded 1, with the value of 1.543 and 1.235. Besides, Arsenic had the highest HQ value (0.957) in Pulsatillae Radix. ConclusionConsuming raw materials of Pulsatillae Radix and Clematidis Radix et Rhizoma may pose a potential risk and Arsenic residues in Pulsatillae Radix deserved special attention.

Contamination level, source identification and health risk assessment of potentially toxic elements in drinking water sources of mining and non-mining areas of Khyber Pakhtunkhwa, Pakistan.

Accelerated mining activities have increased water contamination with potentially toxic elements (PTEs) and their associated human health risk in developing countries. The current study investigated the distribution of PTEs, their potential sources and health risk assessment in both ground and surface water sources in mining and non-mining areas of Khyber Pakhtunkhwa, Pakistan. Water samples (n = 150) were taken from selected sites and were analyzed for six PTEs (Ni, Cr, Zn, Cu, Pb and Mn). Among PTEs, Cr showed a high mean concentration (497) μg L-1, followed by Zn (414) μg L-1 in the mining area, while Zn showed the lowest mean value (4.44) μg L-1 in non-mining areas. Elevated concentrations of Ni, Cr and a moderate level of Pb in ground and surface water of Mohmand District exceeded the permissible limits set by WHO. Multivariate statistical analyses showed that the pollution sources of PTEs were mainly from mafic-ultramafic rocks, acid mine drainage, open dumping of mine wastes and mine tailings. The hazard quotient (HQ) was the highest for children relative to that for adults, but not higher than the USEPA limits. The hazard index (HI) for ingestions of all selected PTEs was lower than the threshold value (HIing < 1), except for Mohmand District, which showed a value of HI >1 in mining areas through ingestion. Moreover, the carcinogenic risk (CR) values exceeded the threshold limits for Ni and Cr set by the USEPA (1.0E-04-1.0E-06). In order to protect the drinking water sources of the study areas from further contamination, management techniques and policy for mining operations need to be implemented.

Hydrogeochemical Evaluation, Groundwater Quality Appraisal, and Potential Health Risk Assessment in a Coal Mining Region of Eastern India

Hydrogeochemical Evaluation, Groundwater Quality Appraisal, and Potential Health Risk Assessment in a Coal Mining Region of Eastern India

Fluoride and nitrate contaminations of groundwater and potential health risks assessment in the Khyber district, North-Western Pakistan

ABSTRACT The current study was conducted to assess the concentration of nitrate (NO3) and fluoride (F), and associated health risks in the four tehsils of district Khyber i.e. Jamrud, Bara, Landi Kotal, and Mula Gori. A total of 61 samples from various groundwater sources were collected and analysed. Groundwater results showed that the mean values of F were 0.86, 0.83, 0.67, and 2.9 mg/l, and that of NO3 15.8, 8.38, 9.76, 4.22 mg/l in Bara, Jamrud, Landi Kotal, and Mula Gori, respectively. Furthermore, health risk assessment was carried out for different age groups i.e. adult male/female (66 years), teens male/female (16 years), and children (6 years). The results revealed that HI values of F through groundwater consuption was > 1 in 39.3% and 16.4% of the samples for children and other age groups (teen and adults), respectively. Similarly, HI values of NO3 for children, adults, and teens were higher than the threshold value in 62.3%, 34.4%, and 39.3% of the samples, respectively. The principal component analysis (PCA)revealed that the predominant source of F enrichment in groundwater was geogenic. However, for the NO3 proportion in the region, the potential causes were agricultural activities. Results revealed that the region requires immediate attention, and remedial measures must be implemented to protect residents from the adverse effects of NO3 and F in the district of Khyber.

Assessment of Potential Health Risk Due to Traffic-Induced Sound Pollution: A Study in Khulna City, Bangladesh

Background: Sound pollution has been emerging as a leading nuisance for urban dwellers all over the world. This study was conducted in some busiest traffic junctions of the Khulna metropolitan city of Bangladesh to reveal the impact of sound pollution on urban dwellers. Methods: The questionnaire survey was conducted using a probability selective sampling procedure and different age groups of respondents were chosen from the five busiest traffic junctures. The necessary associations were discovered using ross-tabulation, Pearson’s Chi-square with Cramer’s V coefficient, and binary logistic regression analysis. Results: Maximum respondents (95%) were found to be affected by several health issues (physical and psychological) due to the current level of road-traffic sound pollution. During the daytime, 98% of respondents claimed the high density of vehicles as a key factor. Meanwhile, 92% of them marked the buses [(χ2(2, n=140)=27.404, p<.0.001) with Cramer’s V coefficient of 0.44] as the most sound generating source. The respondents spending more time in the noisy places were found to have approximately 1.354, 1.311, and 1.221-times higher risk of hypertension, bad temperament, and irregular heartbeat problems, respectively than those who did not report. Notably, hearing loss issues were significantly more common among respondents from various age groups [odds ratio (OR): 1.045, 95% CI: 1.012-1.079]. Conclusion: Traffic sound pollution is harmful to human health. This study suggests that increasing awareness among people along with taking administrative measures would be effective to diminish the sound pollution problem.

Mineral uptake in the leaves of Amaranthus Hybridus and Amaranthus Cruentus harvested in Yaounde farm valleys and Assessment of potential health risks

Mineral uptake in the leaves of Amaranthus Hybridus and Amaranthus Cruentus harvested in Yaounde farm valleys and Assessment of potential health risks

Concentration Levels, Spatial Distribution and Source Identification of PAHs, n-Alkanes, Hopanes and Steranes in Deposited Dust of Mashhad, Iran, and Potential Health Risk Assessment

Concentration Levels, Spatial Distribution and Source Identification of PAHs, n-Alkanes, Hopanes and Steranes in Deposited Dust of Mashhad, Iran, and Potential Health Risk Assessment

Fish Parasites and Heavy Metals Relationship in Wild and Cultivated Fish as Potential Health Risk Assessment in Egypt

Despite wide studies of biomonitoring aquatic environment through dynamics of host–parasite interaction, bio-indicators to track the influence and accumulation of heavy metals on fish are still few. The present study sheds light on the relation between fish parasites and heavy metals as it threatens fish’s health and, as a consequence, that of humans after fish consumption. Samples of Nile tilapia (Oreochromis niloticus) were collected in Burullus Lake, a wild fish source, and from a private fish farm in Kafr El-Sheikh Governorate, in Egypt. They were exposed to various pollutants associated with anthropogenic activities to determine the levels of accumulation of Fe, Zn, and Cu, along with the top three most toxic metals (As, Cd, and Pb) in water and fish tissues of gills, intestine, liver, and muscles in both wild and farmedO. niloticus. The results showed the order of abundance: Fe &amp;lt; Zn &amp;lt; Pb &amp;lt; Cu &amp;lt; As &amp;lt; Cd. In waters of both farmed and wild fish, there was a significant negative relation between parasite prevalence and heavy metals, including Zn, Pb, and As. Also, there was a significant positive relation between parasite prevalence with Cu while no significant relation was found with Fe and Cd. Heavy metal content was significantly higher (p&amp;gt; 0.05) in non-infected than infected farmed and wildO. niloticus. In addition, a significantly decreased concentration (p&amp;gt; 0.05) of essential heavy metal was recorded in wild fish compared to farmed specimens, while non-essential heavy metal was significantly higher (p&amp;gt; 0.05) in wild compared to farmed fish. Bioaccumulation factors (BAF) of different organs ofO. niloticuswere ranked in ascending order: Liver &amp;gt; Gills &amp;gt; Intestine &amp;gt; Muscles. In general, the risk assessment showed safe human consumption of farmed and wild fish under the reported environmental conditions in this study. Moreover, the parasite's presence can be adopted as a surrogate indicator to estimate the potential impact of heavy metal pollution and accumulation.

Trace metal concentrations, fluxes, and potential human health risks in West Africa rivers: a case study on the Bia, Tanoé, and Comoé rivers (Cote d'Ivoire).

Downstream water pollution resulting from anthropogenic pressures on upstream water can cause conflicts, especially in transboundary rivers basins. This study assessed trace metals cadmium, lead, copper, and iron total concentrations, fluxes, and the potential human health risks through ingestion or dermal contact of waters at the mouth of three West African transboundary rivers: the Comoé, Bia, and Tanoé rivers. The results showed highest total concentrations during the months of May and October and statistically comparable concentrations in the rivers. The fluxes discharged to the Atlantic Ocean through the Aby and Ebrie Lagoons are as high as average values found elsewhere in the World. Trace metals lead, copper, and iron fluxes were highest during the month of October in the Bia, Tanoé, and Comoé rivers. The cadmium flux was highest during the month of October in the Bia and Comoé rivers, and during the months of February and December in the Tanoé River, indicating that contamination came mainly from upstream waters and the draining of the river basins. The Pearson correlation analysis showed that the trace metals were mainly from anthropogenic sources including gold mining and agriculture. The total concentrations were lower than international guidelines set by the World Health Organization (WHO). However, the potential human health risk assessment results suggest a significant likelihood of community exposure to harmful effects but not to cancers through water ingestion. This work recommends including small rivers when assessing global river metal fluxes to the ocean and also reducing upstream inputs from human activities to mitigate downstream river water pollution.

Tracing geochemical sources and health risk assessment of uranium in groundwater of arid zone of India

Water quality degradation and metal contamination in groundwater are serious concerns in an arid region with scanty water resources. This study aimed at evaluating the source of uranium (U) and potential health risk assessment in groundwater of the arid region of western Rajasthan and northern Gujarat. The probable source of vanadium (V) and fluorine (F) was also identified. U and trace metal concentration, along with physicochemical characteristics were determined for 265 groundwater samples collected from groundwater of duricrusts and palaeochannels of western Rajasthan and northern Gujarat. The U concentration ranged between 0.6 and 260 μg L−1 with a mean value of 24 μg L−1, and 30% of samples surpassed the World Health Organization’s limit for U (30 μg L−1). Speciation results suggested that dissolution of primary U mineral, carnotite [K2(UO2)2(VO4)2·3H2O] governs the enrichment. Water–rock interaction and evaporation are found the major hydrogeochemical processes controlling U mineralization. Groundwater zones having high U concentrations are characterized by Na–Cl hydrogeochemical facies and high total dissolved solids. It is inferred from geochemical modelling and principal component analysis that silicate weathering, bicarbonate complexation, carnotite dissolution, and ion exchange are principal factors controlling major solute ion chemistry. The annual ingestion doses of U for all the age groups are found to be safe and below the permissible limit in all samples. The health risk assessment with trace elements manifested high carcinogenic risks for children.

Assessment of Potential Human Health Risks from Exposure to Select Heavy Metals in Road Dust Around Mining Sites in Carrascal, Surigao Del Sur, Philippines

Road dust samples around human settlements nearby mining areas in Carrascal, Surigao del Sur, Philippines were investigated to quantify the levels of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) and assess the potential health risks from selected heavy metals. Metal concentrations of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) in road dust were analyzed using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer. Analytical results showed that the average concentrations of Cr, Ni, Mn, and Zn were very high at 15,668, 14,814, 7,054, and 684 mg/kg, respectively. Measured concentrations exceeded standards stipulated in international regulations and guidelines by several orders of magnitude. Mortality and morbidity cases with causes probably related to dust inhalation (e.g., upper respiratory tract infection and pneumonia) noticeably increased during the peak years of mining operations. Non-carcinogenic health risk assessment revealed that children are more prone to develop non-carcinogenic health effects than adults (HI values >1 for Cr, Ni and Mn for children and only Cr for adults), owing to their smaller body weight and activities exposing them to these metals via the ingestion route. Assessment of carcinogenic risk value or the lifetime probability of an individual to develop cancer due to exposure to Ni revealed that such risk is negligible. This study suggests that mining companies and government units should proactively take measures to reduce dust exposure (e.g., dust inhalation) of mine workers and residents in nearby communities. In developing management measures, children should be provided with attention given their greater risk of developing dust-related illnesses and diseases.

Microbial Quality and Potential Health Risks Assessment of Frequently Consume Fresh Fruits and Nuts

Increment in food-borne diseases had become a major concern globally, mostly in the health and socioeconomic sectors. This work was done to appraise the microbiological status of some commonly consumed fresh fruits and vegetables, to ascertain their microbiological load and their impact on the human health. Microbial quality of seven ready to eat (fresh) fruits and nuts (water melon, pineapple, avocado pear, banana, skinned and packaged groundnut, cucumber and pawpaw) were investigated according to standard procedures. Six bacteria species, namely: Escherichia coli, Salmonella, Staphylococcus aureus, Vibrio cholerae, Bacillus and Shigella, were isolated from each sample, by using standard procedures. Findings from the laboratory tests revealed that most of the fruits posed serious hazards and health risks to human beings. Salmonella was the most predominant bacteria in all the food samples, while Vibrio cholerae was the least predominant bacteria in all the food samples, being absent in most of the fruits samples. It was observed that skinned and packaged groundnut, water melon, cucumber and pawpaw were highly infested with pathogenic bacteria; compared to avocado pear, banana and pineapple. This portrayed that the health risks conditions resulting from ingesting packaged groundnut, water melon, cucumber and pawpaw were higher, compared to the risk of ingesting fresh avocado pear, banana and pineapple. Also the health risks assessment results revealed that children consumed higher dosages of microorganism, portraying that they are more susceptible to foodborne diseases. This research discovery had shown the necessity for better food safety surveillance structures, by the health and legal authorities to minimize the incidences of foodborne diseases and infant morbidity.

Potential Health Risk Assessment of Bioaccumulation of Heavy Metals in Freshwater Organisms from Ojo River, Lagos, Nigeria

This study investigated potential health risk associated with heavy metal bioaccumulation in freshwater organisms in Ojo River, Lagos, Nigeria. Liver, gills and muscle from fish samples and muscle and exoskeleton from crab samples were analysed for concentration of Cd, Cr, Zn, Pb, Ni and Cu using Atomic Absorption Spectrophotometer after digestion of samples. Generally, heavy metal concentration in water samples from different locations in Ojo River did not exceed WHO limits. Concentration of Pb, Cu, Zn and Cr in tissues of M. niger and L. campechanus shows high bioaccumulation of heavy metals. Heavy metals bioaccumulated more in liver &gt; muscle &gt; gills in both fish samples. Ni and Cd were not detected in the two fish species. Similarly, Pb, Cu and Ni were found in muscles and exoskeleton of C. pagurus and S. serrate at quantities higher than WHO limits. Zinc was detected only in muscle and not exoskeleton of both crab samples, while Cr was found only in exoskeleton of C. pagurus and Ni was not detected in all crab species. Estimated daily intake (EDIs) for Pb, Cu, Zn and Cr in M. niger and L. campechanus and for Pb, Cu and Ni in C. pagurus and S. serrate were higher than the oral reference doses. Target Hazard Quotient (THQ) for heavy metals were also extremely high. Significantly high bioaccumulation of heavy metals in freshwater organisms from Ojo River calls for serious actions because it is a major source of freshwater foods for residents of Lagos.