Nutritional status and risks of potentially toxic elements in some paddy soils and rice tissues

This experiment was conducted to investigate the potential risk of toxic elements in paddy soils and rice straws, bran, and husked grains in Kuchesfahan, Gilan, Iran. The average content of total and DTPA-extractable of Cd, Cu, Fe, Mn, Ni, Pb, and Zn were 7.0, 26.3, 20728.8, 1516.7, 43.8, 16.6, and 211.8?mg kg^?1, and 0.32, 14.1, 97.3, 63.4, 1.7, 4.8, and 56.2?mg kg^?1, respectively. In addition, the average content of Cd, Cu, Fe, Mn, Ni, Pb, and Zn in rice grain was 0.16, 2.4, 135.5, 34.1, 2.0, 0.6, and 15.0?mg kg^?1, respectively. The average transfer factor for Cd, Cu, Fe, Mn, Ni, Pb, and Zn from soil to straw was 0.38, 0.16, 0.004, 0.13, 0.3, 0.04, and 0.09, respectively. The average values of estimated daily intake for Cd, Cu, Fe, Mn, Ni, Pb, and Zn through rice consumption for adult are respectively, estimated to be 0.0004, 0.005, 0.32, 0.08, 0.005, 0.0015, and 0.035?mg kg^?1 body weight per day. There was no health risk index (HRI) values for adult greater than 1 (except three samples for Fe, and one sample for Mn and Cd); indicated that intake of single metal through the consumption of rice was safe. The average of heath index (HI) value for rice consumption was 0.33 and 0.35 for adult and children, respectively. Therefore, combination of several potentially toxic elements may not cause risk to local residents. Spatial distributions of HRI were obtained for potentially toxic metals in husked grains.     

Integrated risk assessment of potentially toxic elements and particle pollution in urban road dust of megacity of Pakistan

Abstract

Potentially toxic elements and particulate matter (PM) in the ecosystem are regarded as extremely hazardous because of their persistence, toxicity and bioaccumulative characteristics. Therefore, present study was conducted to estimate the ecological and human health risks of potentially toxic elements (Cu, Mn, Pb, Cd and Ni) and particle pollution (TSP, PM₁₀ and PM_2.5) at 2 and 60 m roadside distance from 15 different sites at dust polluted megacity of Pakistan. The AQI assessments suggested that the majority of sites were found unhealthy for sensitive at 2 and 60 m roadside distance, which reveals that that quality of road pavement and streets are far below than the required standards resulting huge quantity of dust particles suspended in air by natural and anthropogenic activities. The maximum geo-accumulation index (I _geo) values (1.47 and 0.52) and pollution index (PI) values (4.18 and 2.15) were observed for Ni at 2 and 60 m distance away from the muddy edge of the roads. Similarly, maximum contamination factor (CF) values (24.5 and 94.5) and ecological risk index (ERI) values (4.11 and 3.15) were found for Cd at 2 and 60 m. The I _geo and PI indicated that the road dust at a distance of 2 m was relatively more contaminated as compared to 60 m roadside distance. Highest cancer risk (CR) values (2.33 adult and 10.9 for children) were observed for Pb at 2 m, while highest CR values (1.21 for adult and 5.67 for children) at 60 m distance. No probable health risk was observed as the total hazard index (HIexp) of all potentially toxic elements was <1. However, children were appeared to be more susceptible to potentially toxic elements. Based on the results, we believe that the exponential increase in traffic load and industries have aggravated the pollution level and it is expected to be increased in the future.     

Spatial distribution of toxic metals in drinking water sources and their associated health risk in district buner,Northern Pakistan

Vigorous knowledge on the occurrence and distribution of toxic metals (TMs) in theenvironment is needed to assess their toxicological impacts on human health especially in developing countries like Pakistan. For the first time, the concentrations of TMs like Ni, Zn, Pb, Cr, and Cd in both ground and surface water and their potential health risk in the district Buner (Pakistan) were determined using Inductive Coupled Plasma Mass Spectrometry (ICP-MS, Agilent Technologies, 7500 CX, USA) and their results were compared with their safe limits defined by Pakistan Environmental Protection Agency (Pak-EPA) and World Health Organization WHO (2008 WHO (World Health Organization). 2008. Guidelines for drinking water quality, First Addendum to third ed. Recommendations, vol 1. Geneva, Switzerland [Google Scholar]). The concentrations of TMs, like Pb (43% and 86%), Ni (63% and 32%), Cr (41%), and Cd (1% and 20%) in drinking water samples exceeded their respective permissible limits set by Pak-EPA and WHO (2008), respectively. The mean concentrations of TMs were found in decreasing order Ni > Pb > Cr > Cd > Zn. The HRI values of TMs in drinking water samples for both adults and children were observed <1 indicating no health risk to the local population. Excessive marble industries are present in the study area; therefore, it is necessary to reduce metal contamination via proper disposal and treatment of marble wastewater, for which the government should take serious action in the study area.     

Sources and risk assessment of toxic elements in the agricultural soil of Tiantai County of Zhejiang province,China

Abstract

The aim of this study was to quantify the pollution level of toxic elements, their ecological risk and human health hazard in the agricultural soil of Tiantai County, Zhejiang province. A total of 2651 soil samples were collected and analyzed for 13 toxic elements using different analytical techniques. The concentration of Cd, Pb, Hg, Mn, and Zn was higher than the Zhejiang background value in more than 50% of samples. Enrichment factor showed that As, Cd, Hg, Mo, Pb, Se, V, and Zn were anthropogenically loaded and most of the toxic elements showed poor spatial distribution. Nemerow pollution index showed that Chicheng, Shiliang, Pingqiao, Tantou, and Youngxi towns were seriously polluted by toxic elements. Principal component analysis and cluster analysis showed that Co, Cr, Ni, and Cu, whereas, Cd, Pb, and Zn shared the similar source of origin. A large area of Tiantai County experiencing moderate to a serious level of pollution but most of the toxic elements exhibit low risk to the environment except Cd and Hg. Furthermore, children were more prone to health hazards than adults with following order: As?>?Cr?>?Pb?>?Mn. Overall, As and Pb were prominent for pollution, ecological risk, and human health hazards.     

Human risk associated with the ingestion of artichokes grown in soils irrigated with water contaminated by potentially toxic elements,Junin, Peru

The contamination of water, air and soil with potentially toxic elements (PTE) compromises the supply of contaminant free food. Vegetables grown in contaminated soils can absorb and accumulate PTE at concentrations that are toxic to human health. In this context, the human risk associated with the intake of artichokes grown in soils irrigated with PTE contaminated water was assessed. 120 samples of surface soil and artichoke heads were collected and the concentrations of Cu, Fe, Pb, Zn and As were determined. The results showed that the concentrations of Cu, Fe and Zn in soil did not exceed the standards of the Ministry of Environment of Peru, but they did exceed those of Pb (125.45 mg kg⁻¹) and As (28.70 mg kg⁻¹). The decreasing order of mean PTE concentration in artichoke heads was Fe > Zn > Cu > Pb > As, exceeding the permissible levels of FAO/WHO CODEX Alimentarius. However, the concentrations of As comply with the maximum limits of inorganic contaminants in vegetables (0.3 mg kg⁻¹) established in the MERCOSUR regulations. The non-carcinogenic and carcinogenic risk of Pb and As indicated that the ingestion of artichoke heads does not represent a health risk.     

Geographical distribution,morphology and water quality of caldera lakes: a review

The geographical distribution, morphometry and water quality of lakes within large calderas (> 2 km in diameter) were evaluated through a review of the literature and maps. Eighty-eight lakes in 75 calderas were located in 31 volcanic subregions. As a group, the lakes varied greatly in elevation, surface area, maximum depth, and shoreline development. The average surface area was 16.9 km², surface elevation 873 m, depth 151.1 m, and shoreline development 1.35. Water quality ranged from ultraoligotrophic to highly eutrophic. None of the lakes had an inlet that originated outside the calderas. Most lakes did not have a surface outlet, were circular or subcircular in shape, and covered only parts of the caldera basins. Water clarity in some lakes was among the highest recorded for freshwater systems, but there are indications of possible declining clarity in some cases. Secondary volcanic activity, such as primary (hydrothermal) water and eruptions, has been associated with deteriorated water quality conditions in some lakes.     

Origin and potential ecological risk assessment of trace elements in the watershed topsoil and coastal sediment of the Oualidia lagoon,Morocco

The Oualidia lagoon provides important ecosystem services, such as fishing, aquaculture, tourism and high biological and ecological productivity. Many indices have been developed to evaluate environmental risks and to estimate the anthropogenic contribution of potentially toxic elements (PTE) in surficial sediments. The results show that the concentrations of the PTE found in surface sediments due to the anthropogenic activities in the area (urban effluents, aquaculture and agricultural areas) are significantly higher than those from the local background and sediment quality guidelines (SQGs). The potential ecological and biological risk index present satisfactory results. However, the sites near to the areas where anthropogenic activities are developed present 49% probability of toxicity, while the rest of the lagoon, present 9% to 21% probability of toxicity and low potential ecological risk, except for Hg where the risk was considered to be considerable. The PTE are mainly originated from the anthropogenic activities; nevertheless, anthropogenic contributions represent up to 69% of the total sediment of content, but it depends on the PTE: Cd (16%), Ni (38%), Zn (41%), Cr (43%), Cu (56%), Hg (68%), Pb (69%). Compared with the Sub-basin soils, the PTE are higher than 80%, hence the sub-basin feeds the lagoon by these elements (PTE).     

Normal concentrations of essential and toxic elements in pregnant baboons and fetuses (Papio species)

Heavy metals are essential for the normal progression of maternal and fetal tissue growth and metabolism in pregnancy. Considerable data have been collected for concentrations of various elements in pregnant women, but no comprehensive evaluation of element concentrations in any non-human primate model has been performed. Baboons were studied at the second half of pregnancy. Forty essential and toxic element concentrations were analyzed by absorption spectrophotometry in paired maternal and fetal blood samples; hair and nail samples in pregnant baboons; in placenta, amniotic fluid; and fetal femur, lymph nodes, and liver. Concentrations demonstrated an excellent correlation with concentrations reported in late human pregnancy. Twenty-four elements were below detectable limits in various specimens. We conclude that the pregnant baboon offers unique opportunities to study both normal maternal, fetal, and placental physiology as well as the environmental toxicology of these elements. This information and the ability to use the pregnant baboon as a model is important because essential and toxic elements are key components of the diet as well as major products of manufacturing processes within our industrialized society.     

Australian water quality guidelines: a new approach for protecting ecosystem health

The Australian and New Zealand Environment and Conservation Council (ANZECC) and the Australian Water Resources Council (AWRC) have developed a National Water Quality Management Strategy which seeks to ensure that the nation's water resources are managed on a sustainable basis. An important element of this strategy are the Australian Water Quality Guidelines which focus on the protection of Australian freshwater and marine ecosystems. Here the aim is to protect biodiversity and maintain the ecological integrity of each marine and freshwater resource. Specific guidelines have been formulated in terms of key indicators of quality, with a single reference value or ranges of reference values provided for guidance. For those indicators where ranges are provided, it is the expectation that State environmental and resource management agencies will undertake local, site-specific investigations of their own systems to define the specific levels to be adopted. For the first time, specific and quantitative biological indicators have been introduced; these are species richness, species composition, primary production, and ecosystem function.As Australia progresses towards broader, more holistic, ecologically-based management of the nation's water resources, the present water quality guidelines must be extended to ecosystem or environmental guidelines, where the maintenance of adequate water quality is seen as only one (albeit important) component. Other considerations must include habitat protection, sediment quality, and stream flow maintenance. This increased emphasis on more ecologically-focused management of Australia's inland and coastal waters will present a number of challenges for the three major groups involved: the community, the managers, and the researchers. These challenges are discussed.Based on a paper presented at a Workshop on Biological Assessment of Aquatic Ecosystem Health, Sydney, 1–2 October 1992.     

Contamination and health risk assessment of trace elements in soil at play centers of urban low-income settings

Abstract

Young children are considered critical receptors of potentially toxic trace elements (PTEs) by non-dietary ingestion of contaminated soil. The study assessed the potential enrichment of soil and the health risk of PTEs to 471 children less than seven years via non-dietary soil ingestion at six Early Childhood Development Centers (ECDCs) in urban low-income settings. The total concentrations of PTEs were determined by ICP-AES after wet acid digestion. The extent of soil contamination with PTEs and their source apportionment were assessed by the enrichment factor (EF). The US-EPA risk assessment model was used to determine the risk of PTE exposure by children. Multivariate statistical analyses and the EF suggested anthropogenic origin of PTEs in playgrounds and indoors, especially Cd and Pb from atmospheric deposition. Indoor floor dust at ECDCs was enriched (significant to extreme) with PTEs of anthropogenic origin imported from the outside environment. Children at the six ECDCs were not at significant non-carcinogenic risk of PTEs in soil and dust through non-dietary ingestion. The study setting is typical of urban child play centers in low-income countries which needs regular risk assessment and the enforcement of legislation in order to reduce the exposure of children to PTEs.     

The Reeuwijk lakes: A five years water quality study in an eutrophic ecosystem

The Reeuwijk Lakes (The Netherlands) present a typical example of eutrophication in the lower Rhine catchment area. In 1986 restoration of these lakes started by reducing the external P-loading. Two lakes, Lake Elfhoeven and Lake Nieuwenbroek, differing in P-load and residence time were selected for monitoring water quality parameters before (1983–1985) and after (1986–1987) these restoration measures. Reduction of the external P-loading did not result in lower P-concentrations in both lakes. In contrast, P and N increased. This may have been caused by an increase in diffuse discharges. However, seasonal cycles of P and N point to a strong internal loading of nutrients. The concentrations of chlorophyll a and carotene decreased, indicating a lower phytoplankton biomass. However, as C-phycocyanine concentrations increased the relative abundance of cyanobacteria became higher. Seston concentrations and zooplankton densities did not change. Transparency in the lakes slightly decreased after P-reduction and is far too low for the development of any vegetation of submerged waterplants. The typical differences between both lakes remained after restoration measures. The inverse relationship between the concentrations of chlorophyll a and total phosphorus at the two sampled stations remained constant. The differences in phytoplankton composition and the zooplankton biomass give a plausible explanation for this inverse relationship, between the two stations. Restoring the lakes after four decades of P-loading can presumably, not simply be done by lowering the external P-load alone. Supplementary in-lake measures may accelerate the restoration process.     

Heavy metals in urban and peri-urban soils of a heavily-populated and industrialized city: Assessment of ecological risks and human health repercussions

Abstract

Increasing levels of heavy metals in soil have become a serious concern for human health because they can be easily transferred into the human body through contaminated food web. It is imperative to evaluate pollution levels, origin and ecological risks of heavy metals. The geoaccumaualtion (Igeo), contamination factor (CF), pollution load index (PLI) and human health risk were estimated to determine the soil pollution in Faisalabad, a heavily-populated and industrialized city of Pakistan. The maximum CF (1.58) and PLI (1.22) values were estimated for Cd and Pb, respectively, and maximum Igeo (?0.19) value was observed for Cd. Correlation analysis and principal component analysis suggested that common industrial sources for Cd and Pb were identified in the study sites. It clearly indicates that the significant levels of heavy metals pollution arise from local industries, busy commercial centers and heavy traffic load in the last few decades in heavily-populated and industrialized city. Further, soil heavy metals concentration were used to evaluate the human health risk such as chronic or non-carcinogenic including hazard indexes HIexP (ingestion, inhalation and dermal and carcinogenic) and cancer risk (CR). The HIexP values of Pb (10.30) and Cd (4.56) were found above the permissible limit (HI = 1) for children. The CR due to carcinogenic metals (Co, Cr and Cd) are within the safe limit (1E-06 to 1E-04). However, CR was comparatively higher in adults as compared to children. The results from the current investigation can help to develop a sustainable strategy in the study region to minimize the entry of heavy metals in food chain through source identification and pollution abatement techniques.     

Evaluation of health risks associated with trace metal exposure in water from the Barekese reservoir in Kumasi,Ghana

Abstract

Reservoirs play a pertinent role in providing potable water to humans and aquatic animals. Exposure to trace metal pollution in water may threaten aquatic ecosystem and human health. In this study, total and dissolved trace metals pollution and health risk they posed to humans in water sampled from the Barekese reservoir in Kumasi were investigated. Levels of Hg, As, Ni, and Cr in the water exceeded the WHO and USEPA stipulated limits. Arsenic and Cd recorded the highest non-carcinogenic health risk to humans. Hazard quotients (HQs) ?1 were recorded for an adult (HQ = 9.05) and a child (HQ = 21.11) via oral exposure to dissolved As in water samples. High HQ values of 40.10 and 17.20 for a child and an adult respectively were recorded through oral exposure for As. HQ of 1.41 was estimated for a child’s risk via dermal exposure to total Cd in water from the reservoir. Cancer risks of 1.63?×?10^?5 and 2.33?×?10^?6 were respectively recorded for a child and an adult oral exposure to dissolved As, suggesting possible adverse effects. The study concludes that anthropogenic activities within the Barekese catchment are deteriorating its water quality.     

城市土地利用异质性对湖泊水质的影响

土地利用类型与水体水质之间存在显著相关关系,这种相关关系受到土地利用类型及其空间分布的影响.人类活动造成流域中不同汇水单元间土地利用异质性,进而影响和改变了汇水单元水质状况.在自然或半自然区域内,采用多个汇水单元的综合分析能够体现出流域土地利用类型与水质的相关关系.然而,在城市区域中,可能存在由于土地利用特征差异而导致这种相关关系的抵消和降低,致使分析结果与实际存在偏差.为证实这一现象的存在,选取武汉市汉阳地区龙阳湖等4个湖泊流域为研究对象,分别从汇水单元综合分析、以影响水质的主要用地类型作为变量进行聚类分析和以湖泊流域为对象的分析等3个角度,分析汇水单元间的土地利用特征差异对水质的影响,结果显示土地利用异质性影响甚至改变了土地利用类型与水质的相关关系.因此,在研究城市土地利用与水体水质相关性时,需要同时考虑土地利用类型的特征和格局.     

Drinking water quality and human health risk evaluations in rural and urban areas of Ibeju-Lekki and Epe local government areas,Lagos, Nigeria

Abstract

This study evaluated the drinking water quality and associated human health risks in three (3) rural and urban areas each in Ibeju-Lekki and Epe local government areas of Lagos, Nigeria. Two hundred structured questionnaires were administered to stakeholders, and samples were obtained from prevailing drinking water sources in the study areas using standard methods for microbiological, physicochemical, heavy metals and human health risk evaluations. Wells and boreholes were the major sources of drinking water in the rural and urban areas, respectively. Drinking water samples from the study areas contained more than one pathogenic bacterium. The physicochemical parameters except total organic carbon (TOC) were within permissible limits of the Nigerian Standard for Drinking Water Quality (NSDWQ). The mean values of Cd and As exceeded the maximum permissible limit of NSDWQ. The hazard quotient of cadmium and arsenic was greater than 1 indicating potential health risks if the water is not treated. In order to achieve the UN Sustainable Development Goal 6 on clean water and sanitation by the next decade (2030), we recommend that frequent monitoring, treatment and stakeholders education on drinking water treatment techniques should be actively conducted particularly in rural areas in the state, country, region and continent.     

Human health risk assessment of trace elements in shallow groundwater of the Linhuan coal-mining district,Northern Anhui Province,China

Enrichment of trace elements in groundwater poses considerable risks to human health. The concentrations of seven trace elements (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) in 34 samples of shallow groundwater from the study area were estimated. We assessed the concentrations of the trace elements and health risks with statistical analysis and the US Environment Protection Agency (USEPA) model. The results showed that the mean concentrations of trace elements decreased as follows: Mn > Zn > Ni > Cr > Cu > Cd > Pb. Apart from Mn at one sampling point, the concentrations of all trace elements were below the guideline values of the World Health Organization for drinking water. Correlation and cluster analysis indicated that the trace elements fell into groups, with Ni and Cu in one group, and Mn, Zn, and Cd in another, which suggested that the trace elements grouped together had similar sources. The total non-carcinogenic risk values ranged from 8.52 × 10^?4 to 1.27 × 10^?1. The total carcinogenic risk caused by Cr and Cd averaged 1.62 × 10^?6, which exceeded the acceptable level of 1 × 10^?6 recommended by the USEPA. The carcinogenic risk of Cr accounted for 75.93% of R_total.     

Spatiotemporal evaluation of trace elements in river water using multivariate methods

The multivariate statistical methods (cluster analysis and discriminant analysis [DA]) are used to evaluate the quality of water spatiotemporally in the Brahmani River basin. A total of 15 water quality indicators (pH, Chloramines, Sodium, Sulfate, Phosphate, Potassium, Boron, Fluoride, Cadmium, Copper, Lead, Nickel, Zinc, Iron, and Total Chromium) are collected for 13 years in two seasons (the dry and the wet season) from nine sampling stations. These stations are grouped into four clusters (Considerable [Co], Low Pollution [LP], Moderate Pollution [MP], and Extreme Pollution [(EP]) by hierarchical agglomerative cluster analysis based on the similarities of water quality characteristics. The nine important influencing discriminating water quality indicators are extracted by stepwise method of temporal DA,where as eight important influencing indicators for dry season and eight indicators (Potassium, Phosphate, Fluoride, Copper, Lead, Nickel, Iron, and Total Chromium) for wet season are found out by the spatial DA. The pollution status in the river basin was observed from overall trend in (Considerable) Co to (Extreme Pollution) EP regions. The study could be very useful in prioritizing the important sites for water resources and pollution management.     

Assessment of spring water quality and quantity, and health implications in Tongaren division, Nzoia River catchment, Kenya

Spring water is the common source of public water supply in most rural communities of developing countries such as Kenya. The water quality and quantity may be altered due to catchments degradation. This study was carried out in Tongaren division, Nzoia River catchment. The aim of this study was to investigate and map the occurrence and distribution of springs and to determine their water quality and quantity. This study determined the spring water discharge, conductivity, turbidity, total and thermotolerant (faecal) coliforms to assess suitability and sustainability of spring water for safe drinking. Twenty-eight springs were identified and their locations mapped using Global Positioning System (GPS) geo-reference data. Discharge ranged from 0.1 to 3 l s⁻¹, with some drying up during dry season. Total coliform was innumerable in most of the studied springs while thermotolerant (faecal) coliform counts occurred in eight springs, including four protected springs. This poses high risks of water-borne diseases. The water should be filtered and boiled prior to use for drinking. Facilitation of communities enabled development of seven springs to enhance water yield and quality. This study established high potential in the communities to develop springs and utilize the spring water as alternative source of livelihoods.     

城市河湖生态系统健康评价——以北京市“六海”为例

健康的城市河湖才能发挥生态环境功能,体现景观和人文价值。城市河湖健康评价是城市河湖科学管理和生态恢复的前提和基础。对城市河湖生态系统健康概念和内涵进行了探讨,建立了评价指标体系和评价模型。以北京“六海”为例,对各子湖的健康状况进行比较评价。结果表明,中海和南海处于不健康向临界转化的状态,其余4个湖均处于不健康状态;水环境质量、水生态系统结构和功能以及水滨空间结构是影响“六海”健康水平的制约因素;除南海外,各湖的健康程度都处于很差的级别。中海和南海的整体生态环境好于其余4湖,对健康和临界状态的隶属度之和接近0.6,可恢复程度处于中等水平;其余4湖对健康和临界状态的隶属度之和均小于0.3,恢复困难。对“六海”的生态恢复和科学管理提出建议:①控制点源、面源污染,改善入湖和湖水水质;②改善“六海”的水文条件;③恢复水生态系统结构和水滨空间。