Route Of Intake Research Articles

Assessment of heavy metal concentrations, environmental risks and human health implications in marine sediments along the coastal ecosystems of the Republic of Congo.

The aim of this study is to assess the level of heavy metals (HMs) in surface sediments along the coastal estuaries of the Republic of Congo. A variety of approaches were employed, integrating elemental analysis (Atomique Absorption Spectroscopy), environmental, ecological, health risk assessment, and source identification techniques to evaluate the distribution, origin, environmental, ecological and health risks of potentially toxic element (PTE) contamination in sediments. The ascending mean concentration (mg/kg) of Cd (0.4) < Cu (18.6) < Pb (28.8) < Zn (62.1) < Mn (107) < Mg (569.6) complied with the local background, except for Cd and Pb. However, notable variations across sampling points and sites were observed, with a strong relationship between metals and organic matter. The comparing of PTEs with USEPA international standards and sediment toxicity guidelines showed compliance. The assessment of environmental risk parameters, based on the calculation of the geo-accumulation index, concentration factor and pollutant load indices showed low pollution of sediments. The ecological risk assessment, on the other hand, revealed a low level of pollution of biota and a low toxicity risk of ecosystems related to Cd and Pb and then to Cu in some sites. Regarding human health risk assessment, related to the PTEs, the cancerogenic effect indices were calculated for Cd and Pb through ingestion and inhalation pathways, and the non-cancerogenic effect indices were calculated for all HMs through ingestion, inhalation, and cutaneous contact routes, for children and adults, and showed that the results comply with the international standards set by USEPA, ranging from 10-4 to 10-6 and less than 1, respectively, where children were more sensitive and vulnerable than adults to the effects of the PTEs. Ultimately, this study revealed sediment lithology, anthropogenic activities, and mixed origins of HMs, with a large contribution from industrial activities. However, no significant impacts are discernible in the study area. In addition to the importance of this study, it forms part of the region database and could serve as a reference for future monitoring studies, since no data are available in th Congolese coastal environment.

Health risk assessment of lead, cadmium, heavy metals and metalloids in residential paint flakes from indoor wall surfaces.

Paint components pose risky metals like lead, cadmium, arsenic, and mercury that endanger occupants, mainly children and pregnant women. To assess the levels and health risks of 14 metals in paint flakes from indoor walls of residential houses in four states in South-western Nigeria. Flaked paints were collected from 144 houses where children reside. Metals were analysed using an inductively coupled plasma-optical emission spectrometer. The cadmium (Cd), lead (Pb), arsenic (As), and chromium (Cr) levels (mg/kg) ranged from 1239.9 to 2254.2, 1126.5 to 3080.3, 822.1 to 1492.0, and 2.5 to 60.6 in all the state capitals examined, respectively. All samples examined in this study were above the regulated permissible limits. The US Environmental Protection Agency estimated health risk assessment model was used to calculate the chronic daily intake, hazard quotient, hazard index (HI), and lifetime cancer risk (LCR). HI > 1 was highest in the ingestion route (2.592341: adults, 24.5153: children), and the LCR in children and adults followed the order of LCRingestion > LCRinhalation > LCRdermal. The probability of developing cancer over a lifetime, Total Lifetime Cancer Risk, for children exceeded the limit range for Pb, Mn, and Zn in the paint flakes from all the buildings, while almost all buildings where children resided exceeded the limit range for Cd. The study revealed that paint flakes from indoor walls pose a significant source of metal contamination and health risk, especially for children. In Nigeria, there is a need for stricter regulation and monitoring of metal content in paints and paint flakes.

Is gastrointestinal epithelial barrier dysfunction the only responsible for sensitization to food allergens?

Epithelial barriers are crucial defenses against pathogens and allergens, and recent theories suggest that environmental factors may compromise them, leading to type 2 inflammation and conditions such as asthma, atopic dermatitis, food allergy, and rhinitis. While skin and respiratory barriers show clear dysfunctions in allergies, the role of the gut epithelium is less defined, particularly in view of its ability to absorb nutrients and maintain immune tolerance under normal conditions. Research indicates that gastrointestinal barrier integrity typically remains preserved in food allergies, allowing for the development of immune tolerance to ingested food antigens through mechanisms like Treg cells and IgA. Allergies to cow's milk or hen's egg proteins most often resolve with age, highlighting the gut's evolving role in allergen sensitization. Studies like the LEAP (Learning Early About Peanut Allergy) trial demonstrate the preventive benefits of early allergen exposure against peanut allergy, supporting the dual allergen exposure hypothesis. New allergens such as alpha-Gal and gibberellin-regulated proteins (GRP) reveal distinct sensitization pathways beyond traditional ingestion routes, implicating non-dietary sources in allergen introduction. Altogether, there is lack of evidence suggesting that the intestinal epithelium is disrupted in food allergy.

Uptake, removal and trophic transfer of fluorescent polyethylene microplastics by freshwater model organisms: the impact of particle size and food availability

As an emerging contaminant, microplastics (MPs) are widely distributed in freshwater ecosystems and pose potential threats to aquatic organisms, attracting significant attention from both the scientific community and the general public. However, there is still uncertainty regarding the mechanisms of MPs transfer within aquatic biota and how particle size and food availability influence their transport patterns. In this study, zebrafish (Danio rerio) were selected as a model organism to investigate the uptake and elimination of fluorescent polyethylene (PE) MPs under different exposure scenarios (waterborne or trophic transfer, with or without food) and varying particle sizes (ranging from 10-300 μm at concentrations of 0.1, 2, and 300 mg/L). Additionally, water fleas (Daphnia magna) were provided as prey for the fish. The dynamic accumulation of PE-MPs sized between 10-20 μm at a concentration of 25 mg/L by daphnia was also determined along with its impact on animal feeding behavior. The results demonstrated that both organisms were capable of ingesting PE-MPs during exposures lasting up to 24 hours for daphnia and up to 72 hours for zebrafish. Furthermore, rapid elimination rates were observed within just 30 minutes for daphnia and between 6-12 hours for zebrafish. The presence of food reduced MPs uptake and removal by daphnia but significantly increased MP elimination by fish. Zebrafish showed a preference for ingesting larger-sized MPs that they could easily recognize; however, trophic transfer from daphnia to fish was found to be the primary route of ingestion specifically for PE-MPs sized between 10-20 μm. The findings suggest that while fish directly ingest fewer invisible MPs from the water column, they still accumulate these particles through predation on contaminated prey organisms. Therefore, it is imperative to prioritize the ecological risks associated with the transfer of MPs from zooplankton to fish.

Health Risk Assessment of Trace Elements in Surface Water from Dayat Roumi Lake, Morocco

To assess the human impact on the water of Dayat Roumi Lake and to develop effective management strategies to protect and restore this vital ecosystem in the region, seasonal sampling was carried out at six stations distributed around the lake. During these sampling campaigns, 24 parameters were measured, including 20 trace elements. Results showed that measured levels of trace elements increased in the following order: Cd &lt; Be &lt; Tl &lt; Co &lt; Sb &lt; Mo &lt; Cu &lt; Zn &lt; Ni &lt; V &lt; Rb &lt; Mn &lt; As &lt; Cr &lt; Pb &lt; Li &lt; Ba &lt; Se &lt; Pd &lt; Sr in the lake water and that these recorded values were lower than those recommended by the Moroccan standard and the World Health Organization, except for Pb and Se. Correlation analysis revealed two principal water-contamination sources: natural geological origins and anthropogenic inputs. In addition, the Water Quality Index WQI showed that the lake’s water quality is poor, and its use can be dangerous for human and animal health. Health risk assessment associated with prolonged exposure to trace elements in lake water revealed that the Hazard quotient HQ and Hazard index HI of certain elements, such as Tl, Sb, V, As, Cr, Pb, Li, and Se, are higher than 1 in adult and children, indicating a significant risk for people living near the lake. Children are particularly vulnerable, with higher levels of HQ and HI, and selenium poses a substantial risk to their health through ingestion and skin absorption. In both adults and children, the total risk of cancer due to metals is classified as follows: CI (Cr) &gt; CI (Ni) &gt; CI (As) &gt; CI (Pb) &gt; CI (Cd). The Cr presents the highest carcinogenic risk—by ingestion or dermal route—in both groups. The total risk for these five metals exceeds 1 × 10−4, indicating a danger for residents who drink or swim in the lake.

Ignoring the food route underestimated human health risk from potentially toxic elements in agricultural environments of Ziyang, Shaanxi, China.

Staple food is a crucial exposure route for the human intake of potentially toxic elements (PTEs), but it has been neglected in previous human health risk (HHR) studies. Lack of attention to this issue will lead to an underestimation of HHR caused by PTEs. This study establishes a comprehensive regional identification method for health risk assessment (HRA), namely, soil-maize health risk assessment (SMHRA) and applies it to Ziyang, Shaanxi, which is a typical agricultural county. SMHRA considered the exposure pathway of staple food and utilized Monte Carlo simulation to enhance the accuracy of HRA for PTEs. Results indicated the PTE spatial heterogeneity in a soil-maize system. Introducing staple food exposure pathway would increase HHR values and probabilities 1.57-2.80 and 1.53-5.63 times than that when food route was not considered. Overall, the HHR caused by a single PTE was low, which relatively safe. The introduction of food pathway contributed to accurate estimate the HHR of As and Ni, and the risk probabilities ranged from 0.04% to 12.46%. Few areas had high levels of Ni, which pose health risks: approximately 1.8% for children and higher than 0.5% for adults. Both As and Ni had the highest contribution to HHR among all PTEs, with 33.84%-41.56% TNCR caused by As, and 54.73%-56.90% TCR created by Ni, respectively. For human health risk routes, the staple food exhibited the highest contribution to HHR among all exposure routes, with TNCR of 36.15%-56.73% and the TCR of 44.96%-64.28%. Our research imply that dietary intake of PETs must be considered in the human health risk assessment in agricultural environment, which offers the foundation for subsequent environmental risk prevention and control.

Water Quality Analysis and Risk Assessment of Potential Toxic Elements in Selected Surface Water Around Mining Sites in Abuakwa South Municipal, Ghana

ABSTRACTSurface water quality at Abuakwa South Municipal has received threats from surrounding mining communities, which are becoming a major concern to the public. As a result, this study aimed to assess water quality by examining the concentration of lead (Pb), cadmium (Cd), and zinc (Zn) pollution in surface water. Fifteen samples were obtained from surface water using a 1.5 L plastic bottle. The mean concentrations of Pb and Cd were above WHO guidelines of 0.01 and 0.003 mg/l, respectively, except for Zn which was below the stipulated limit of 3.0 mg/l. The geochemical process model shows that Cd, Pb, and Zn are adsorbing (released from the drainage to the surrounding environment) in sites 1 and 3 whereas Pb is desorbing (added to the drainage) in site 2. A hazard quotient greater than 1 was recorded for Cd in adults through the ingestion route of exposure at all the sites. Cancer risk also shows that the inhabitants are at risk through the ingestion route of exposure. The findings of this study suggest intake of water draining within the vicinity is unsafe and poses severe health risks.

Levels, distribution, and health risk assessment of phthalic acid esters in urban surface soils of Nagpur city, India.

Surface soil samples from residential, commercial, and industrial areas of Nagpur city, India, were collected to study the levels, distribution, and impact of land use patterns on phthalic acid ester (PAEs) contamination. The Σ6PAEs concentrations in soils from residential, commercial, and industrial areas ranged between 6,493 to 13,195µg/kg, 707 to 18,446µg/kg, and 1,882 to 5,004µg/kg with medians of 10,399, 6,199, and 3,401µg/kg, respectively. Bis-2-ethylhexyl phthalate (DEHP) and dimethyl phthalate (DMP) were the dominant PAEs in the urban soils. The concentrations of DEHP and DMP were significantly greater than those in Ontario's soil quality guidelines. Among the PAEs, benzyl-butyl phthalate (BzBP) was found at relatively high concentrations (1,238 and 9,171µg/kg) at two locations (i.e., S1 and S15). The chronic toxic risk (CTR) of PAEs was below the threshold, although the risk to children through ingestion and dermal exposure routes was greater than that to adults. The CR due to BzBP and DEHP were below the threshold level; however, the CR due to DMP was > 1 × 10-6 in residential areas. The cumulative CR of the six PAEs for adults (1.33-1.41 × 10-5) and children (8.08-8.89 × 10-6) surpassed the threshold level. This study revealed that PAEs in urban soils pose a risk to public health and require immediate risk reduction strategies.

Occurrence and profiles of bisphenol A and its analogues in marine shrimps from Tianjin and their implications for human exposure

Bisphenols, a class of compounds with endocrine-disrupting characteristics, encompassing its effects on reproduction, nervous and immune systems. Diet represents the principal route of bisphenols intake, prompting concerns about dietary exposure. In this study, the occurrence and content of nine bisphenols in 96 marine shrimps from Tianjin were detected and analysed using ultra high performance liquid chromatography mass spectrometer and solid-phase extraction. The analytical method was validated to demonstrate reliable analytical performance. The results revealed that bisphenol A was detected in the majority of the samples, with the highest detection rate among the nine bisphenols, followed by bisphenol S, while the remaining bisphenols were not detected. A discernible age-related trend was identified in the assessment of dietary exposure, whereby exposure levels increased with decreasing age. Furthermore, regional discrepancies were observed, yet no gender-based distinctions were discerned. The estimated daily intake to total bisphenols through marine shrimp in this study was lower than the current tolerable daily intake set by the European Food Safety Authority, and it can be assumed that the risk of exposure to the nine bisphenols investigated through dietary is acceptable. However, given the recently proposed draft values by the European Food Safety Authority and the higher exposures observed in children and teenagers, further surveillance and dietary guidance is required. To our knowledge, this is the first study in Tianjin to evaluate the health risks associated with bisphenol A and its analogues via marine shrimp, which can monitor dietary safety and protect population health.

Epidemiologic and clinical features of cyanobacteria harmful algal bloom exposures reported to the National Poison Data System, United States, 2010–2022: a descriptive analysis

BackgroundHarmful algal bloom occurrences have been increasingly reported globally and over time. Exposure to the variety of toxins and co-contaminants that may be present in harmful algal blooms can cause illness and even death. Poison control data is a valuable public health information source that has been used to characterize many types of toxin exposures, including harmful algal blooms. Prior studies have been limited by location and time, and knowledge gaps remain regarding cyanobacteria harmful algal bloom (cyanoHAB) exposure circumstances, and the breadth and severity of associated clinical effect.MethodsThe objective of this study was to characterize epidemiologic and clinical features of cyanoHAB exposure cases reported to 55 US poison control centers and available in the National Poison Data System (NPDS). We identified 4260 NPDS cyanoHAB exposure cases reported from 2010 to 2022, including symptomatic exposure cases with and without clinical effects related to the exposure and asymptomatic exposure cases. We assessed demographics; exposure routes, locations, chronicity; clinical effects; and medical outcomes. We calculated case rates annually and 13-year case rates by US geographic division.ResultsOver half of cyanoHAB exposure cases were children < 20 years old (n = 2175). Most cyanoHABs exposures occurred in a “public area” (n = 2902, 68.1%); most were acute (≤ 8 h) (n = 3824, 89.8%). Dermal and ingestion routes and gastrointestinal effects predominated. 2% (n = 102) of cases experienced a moderate or major medical outcome; no deaths were reported. National rates increased from 0.4 cases/1 million (1 M) person-years in 2010 to 1.4 cases/1 M person-years in 2022. The Mountain division had the highest 13-year rate (7.8 cases/1 M person-years).ConclusionsCyanoHAB exposure case rates increased 2010–2022, despite a decrease in all-cause exposure cases during the same period. NPDS data provide valuable public health information for characterization of cyanoHAB exposures, an emerging public health challenge.

Intake rates of methylmercury in the Belgian population: Evolution over 40 years

Methylmercury (MeHg) is one of the most toxic compounds, it bioaccumulates and biomagnifies along the food chain and finally damages human's nervous system. Knowing that the main intake route for MeHg in humans is through fish consumption, intake rates were studied in various countries, but not in Belgium. Based on Hg and MeHg measurements in various fishes, mainly from North Sea catches, in combination with the national food consumption surveys, we could calculate daily Hg and MeHg intake rates for the Belgian population in 1975, 1997 and 2014–2021. These values are then compared with daily intake values reported by other countries and with the acceptable daily intake (ADI) values recommended by international organizations. Daily Hg and MeHg intake rates decreased strongly between 1975 and the 2 later periods: while average intake rates are all below the ADI norms, this is not the case for the 95th percentile rates because they exceed or are very close to the ADI values. Since daily MeHg intake rates correlate well with hair and blood concentrations, these were used as a good proxy of MeHg intoxication and were related to health effects observed in children, adolescents, adults and elderly persons living in Belgium via biomonitoring.

The route of nutrition intake in post intensive care patients

The route of nutrition intake in post intensive care patients

Acute gastrointestinal symptoms associated with oil spill exposures among U.S. coast guard responders to the Deepwater Horizon oil spill

PurposeResearch investigating gastrointestinal (GI) symptoms from oil spill-related exposures is sparse. We evaluated prevalent GI symptoms among U.S. Coast Guard responders deployed to the Deepwater Horizon oil spill cleanup. MethodsCrude oil (via skin contact, inhalation, or ingestion routes), combined crude oil/oil dispersant exposures, other deployment exposures, deployment characteristics, demographics, and acute GI symptoms during deployment (i.e., nausea/vomiting, diarrhea, stomach pain, and constipation) were ascertained cross-sectionally via a post-deployment survey (median time between deployment end and survey completion 185 days) (N = 4885). Log-binomial regression analyses were employed to calculate prevalence ratios (PRs) and 95 % confidence intervals (CI). Effect modification was evaluated. ResultsIn adjusted models, responders in the highest (versus lowest) tertile of self-reported degree of skin contact to crude oil were more than twice as likely to report nausea/vomiting (PR=2.45; 95 %CI, 1.85–3.23), diarrhea (PR=2.40; 95 %CI, 2.00–2.88), stomach pain (PR=2.51; 95 %CI, 2.01–3.12), and constipation (PR=2.21; 95 %CI, 1.70–2.89). Tests for trend were statistically significant (p < 0.05). Results were similar for crude oil exposure via inhalation and ingestion. Higher PRs for all symptoms were found with combined crude oil/dispersant exposure than with crude oil exposure alone. ConclusionsThese results indicate positive associations between self-reported crude oil and combined crude oil/oil dispersant exposures and acute GI symptoms.

Respiratory system: Highly exposed yet under-reported organ in pyrethrin and pyrethroid toxicity.

Pyrethrin and pyrethroid are a relatively new class of pesticides with potent insecticidal properties. Pyrethrins are naturally occurring pesticides obtained from the Chrysanthemum cinerariaefolium flower, while pyrethroids are their synthetic derivatives. They are widely used as the insecticides of choice in agriculture, veterinary medicine, public health programs, and household activities. Pyrethrin, being a broad-spectrum insecticide kills a wide range of pests, while pyrethroids last longer in the environment owing to low susceptibility to sunlight, and greater stability and efficacy than parent molecules. Humans can be exposed through inhalation, ingestion, and dermal routes. Indoor usage of an insecticide poses a serious risk to human health, especially to women, children, and stay-at-home people. Although pyrethrin and pyrethroid are generally considered safe, sustained skin or inhalation exposure or direct contact with open wounds results in higher toxicity to mammals. There is a paucity of data on the impact of pyrethrin and pyrethroid on overall pulmonary health. The respiratory system, from the nose, nasal passages, airways, and bronchi to the pulmonary alveoli, is vulnerable to environmental contaminants such as pesticides because of its anatomical location as well as being a highly blood profused organ. Under and over-functioning of the respiratory system triggers diverse pathologies such as serious infections, allergies, asthma, metastatic malignancies, and auto-immune conditions. While the association between workplace-related pesticide exposures and respiratory diseases and symptoms is well documented, it is important to understand the adverse health impact of pyrethrin and pyrethroid on the general population for awareness and also for better regulation and implementation of the law.

Evaluation of fluoride exposure using disability-adjusted life years and health risk assessment in south-western Iran: A novel Monte Carlo simulation

Consumption of fluoride-contaminated water is a worldwide concern, especially in developing countries, including Iran. However, there are restricted studies of non-single-value health risk assessment and the disease burden regarding fluoride intake nationwide. Prolonged exposure to excessive fluoride has been linked to adverse health effects such as dental and skeletal fluorosis. This can lead to under-mineralization of hard tissues, causing aesthetic concerns for teeth and changes in bone structure, increasing the risk of fractures. As such, we aimed to implement probability-based frameworks using Monte Carlo methods to explore the potential adverse effects of fluoride via the ingestion route. This platform consists of two sectors: 1) health risk assessment of various age categories coupled with a variance decomposition technique to measure the contributions of predictor variables in the outcome of the health risk model, and 2) implementing Monte Carlo methods in dose-response curves to explore the fluoride-induced burden of diseases of dental fluorosis and skeletal fractures in terms of disability-adjusted life years (DALYs). For this purpose, total water samples of 8053 (N=8053) from 57 sites were analyzed in Fars and Bushehr Provinces. The mean fluoride concentrations were 0.75 mg/L and 1.09 mg/L, with maximum fluoride contents of 6.5 mg/L and 3.22 mg/L for the Fars and Bushehr provinces, respectively. The hazard quotient of the 95th percentile (HQ>1) revealed that all infants and children in the study area were potentially vulnerable to over-receiving fluoride. Sobol’ sensitivity analysis indices, including first-order, second-order, and total order, disclosed that fluoride concentration (Cw), ingestion rate (IRw), and their mutual interactions were the most influential factors in the health risk model. DALYs rate of dental fluorosis was as high as 981.45 (uncertainty interval: UI 95 % 353.23–1618.40) in Lamerd, and maximum DALYs of skeletal fractures occurred in Mohr 71.61(49.75–92.71), in Fars Province, indicated severe dental fluorosis but mild hazard regarding fractures. Residents of the Tang-e Eram in Bushehr Province with a DALYs rate of 3609.40 (1296.68–5993.73) for dental fluorosis and a DALYs rate of 284.67 (199.11–367.99) for skeletal fractures were the most potentially endangered population. By evaluating the outputs of the DALYs model, the gap in scenarios of central tendency exposure and reasonable maximum exposure highlights the role of food source intake in over-receiving fluoride. This research insists on implementing defluoridation programs in fluoride-endemic zones to combat the undesirable effects of fluoride. The global measures presented in this research aim to address the root causes of contamination and help policymakers and authorities mitigate fluoride's harmful impacts on the environment and public health.

Association between spectrum of mycotoxins and semen quality: A cross-sectional study in Beijing, China

Exposure to mycotoxins is unavoidable in daily life through ingestion, dermal, and inhalation routes. Toxicological studies found that exposure to mycotoxins might affect male reproductive function. However, there is still a lack of population evidence. We aimed to assess the association of individual and joint exposure to spectrum of mycotoxins with semen quality. The present study included 192 participants in Beijing, China. We measured conventional semen parameters and assessed semen quality. Sixty-seven traditional or emerging mycotoxins were determined to describe the spectrum of mycotoxins. The participants were widely exposed to multiple mycotoxins, and nearly half were simultaneously exposed to more than six mycotoxins. After adjusting potential confounders, logistic regression indicated that the number and concentration of plasma mycotoxin were correlated to the risk of low semen quality. Plasma beauvericin and citrinin concentrations were associated with lower semen quality. The least absolute shrinkage and selection operator regression showed similar results to logistic regression. Quantile-based g-computation and Bayesian kernel machine regression models found that the mixture of mycotoxins was harmful to semen quality, especially in sperm motility. In conclusion, both individual and mixture of mycotoxin exposure were correlated with lower semen quality. More regulations and measures should be taken to reduce mycotoxin contamination.

HERisk and statistical clustering integrated for health risk modelling of PTEs in natural water resources for drinking and sanitary uses

Potentially toxic elements (PTEs) are well-known for exposing living organisms and humans to different levels of risk. The present study aimed to evaluate the extent of exposure to health risks sustained by the inhabitants of different suburbs across Southeastern Nigeria as a result of contaminated water sources. There are existing literatures on human health risk assessment in the study region. However, this is the first study to report a detailed breakdown of the risks faced by nine age groups in the study area. This was achieved by integrating a novel code (HERisk), statistical clustering, and water quality data. Laboratory analysis showed that the levels of PTEs (Fe2+, Ni2+, Cr3+, and Pb2+) in 53.6%, 17.8%, 3.5%, and 46% of the samples were found to be above the recommended limits. Aggregated human health risk scores for ingestion and dermal routes revealed that children aged 1 to 2 years are the most vulnerable to health hazards. According to cumulative carcinogenic health risk values (0.00E+00 to 2.41E-04), samples proximal to regions with significant human activities expose the locals to a high risk of developing cancer via ingestion. Q-mode hierarchical cluster analysis successfully validated the classification schemes used for the interpretation of the HERisk code values, captured the patterns in the dataset, and brought forth new perspectives. The comprehensive approach detailed in this study can be adopted as a framework for ongoing monitoring and assessment of water quality.

Concentrations and Health Risk Valuation of Possibly Toxic Metals in Soil and Sediment in Parts of Ona River, Ibadan, Nigeria

The accumulation of contaminants in the soils and sediments may negatively affects people within the vicinity of Ona River and increase potential of human health risk. This study appraised the concentration status, probable origins and human health risks of some possibly toxic elements (Fe, Cu, Zn, Mn, Pb and Cd) in the riverbank soils (RBK) and riverbed sediments (RBS) of Ona River section bordering residential community in Ibadan, Southwest Nigeria. Therefore, six composite samples of RBK and RBD were analyzed for heavy metals using atomic absorption spectrophotometry (AAS). Enrichment factor (EF) and quantification of contamination (QoC) are used to examine potential origins of tested metals. Furthermore, hazard index (HI) and total cancer risk (TCR) have been utilized to evaluate the extent of non-carcinogenic and cancer risks of studied metals to inhabitants of the study site. The results of metal contamination assessment revealed low concentration &lt;1.0 mg/kg for each analyzed metal in both RBK and RBD while EF and QoC advocate lithogenic origins of assessed metals with little or none anthropogenic inputs in both studied soils and sediments. The computed HI values were lower than 1.0 and thus no adversative health effects on adults and children via ingestion, skin contact and inhalation routes. The CR computation exposed that adults and children are at growing risk of developing cancer over a lifetime when exposed to RBK and RBD via ingestion and dermal pathways. Cadmium contributed largely to TCRs among the assessed metals. The study indicates the inevitability of initiating actions that reduce exposure of residents to nearby soil and sediment and safeguard their health, particularly the children.

Impacts of unregulated dumpsites: a study on toxic soil contamination, associated risks, and call for sustainable environmental protection in Nnewi, Nigeria

The accumulation of leachates from unlined dumpsites laden soil-water environment with toxic elements poses imminent threats to both the environment and humans. This study evaluated the seasonal levels of potentially toxic elements (PTEs), their health-related risks, contamination factors (CF), pollution load index, geo-accumulation index (Igeo), ecological risk index, polymetallic contaminant index and Nemerow's synthetic pollution index of soils near a waste dump in Nnewi, Anambra State, Nigeria. The PTE results indicated that levels of Cd (1.54–3.40 mg/kg) were above the World Health Organization's threshold limit for soil. The studied soil samples had PTE levels higher than the control samples due to their proximity to the dumpsite. The CF of the PTE in the soil indicated moderate to considerable contamination, while the control areas showed moderate contamination for both seasons. The pollution load indices of the soil indicated heavy and moderate pollution for the study sample (2.207–2.517) and control samples (1.445–1.659). However, the ecological risk indices ranged from 85.72 to 164.84, indicating a low ecological risk. The Igeo of the PTE in the soil ranged from unpolluted, moderately polluted to very strongly polluted. The Nemerow's synthetic pollution index values ranged from 3.560 to 3.564 for the study samples and 2.070–2.502 for the control samples, indicating heavy and moderate pollution of the soil respectively. The polymetallic contaminant index values for the study samples (23.22–26.43) and control samples (15.02–17.23) showed high and considerable contamination respectively. Health risk examination highlighted that both adults and children have a low risk for non-cancer health threat via ingestion route, while a high risk was obtained for children for cancer health dangers via ingestion routes. For the dermal pathway, children and adults have minimal chances of exposure to cancer risks, while a high exposure to non-cancer risk was observed for children. Pearson's correlation and principal component loadings revealed the sources of pollution to be of similar origins linked to anthropogenic activities. Awareness programs are necessary to educate the populace about the dangers of using contaminated soil for farming or recreational activities. The use of sanitary dumpsites should be encouraged and adopted as a waste disposal method by the government to mitigate the spread of PTE into the environment.

Human health and ecological risk assessment of heavy metals in topsoil of different peatland use types

Peatlands, known for their ability to retain and immobilize heavy metals due to unique waterlogged conditions and organic matter, face challenges when subjected to disturbances such as land use changes. These disruptions alter the organic matter, redox potential, and pH of the peatsoil, potentially influencing the migration, mobilization, and increased availability of stored heavy metals. Peatsoil samples from various peatland use types (improved and semi-natural grassland, forest, industrial cutaway bog) were collected to assess the human health and ecological risk associated with heavy metals (Cd, Cu, Hg, Pb, and Zn) in Co-Offaly, Ireland. Results reveal variations in heavy metal concentrations across peatland use types, with Cd, Hg, and Pb in improved and semi-natural grassland peatsoils exceeding the World Health Organization (WHO) permissible safety limits. Contamination factors (CF) were higher in improved grassland, especially for Cd and Pb, exceeding one. Hakanson potential ecological risk assessment indicates acceptable overall risk levels, though variations exist between improved grassland, unimproved grassland, forest, and industrial cutaway bog. Combined exposure routes (dermal, ingestion and inhalation routes) to all heavy metals do not exceed safe exposure levels (indicating low non-carcinogenic risks. However, the cancer risk (CR) exceeds acceptable thresholds across all use types, with higher CR in improved grassland, especially for children. Overall, the findings emphasize the need for careful consideration of heavy metal risks associated with land use changes in peatlands, particularly in the improved grassland areas.