Pollution Status Of Heavy Metals Research Articles

Traceability Analysis and Environmental Quality Assessment of Soil Heavy Metal Pollution in West Hunan Province

In order to explore the status of soil heavy metal pollution and environmental quality in west Hunan, relevant areas of Phoenix County were selected as the study area. Using data from 440 soil samples collected in the study area from June to August 2022, the pH value of the soil and contents of eight heavy metal elements, namely, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, were analyzed. The PMF model was used for traceability analysis and geochemical evaluation of soil environmental quality. The results showed that the average values of soil heavy metals ω(Zn), ω(Cr), ω(Pb), ω(Ni), ω(Cu), ω(As), ω(Cd), and ω(Hg) were 81.02, 64.67, 31.63, 29.27, 25.52, 9.93, 0.28, and 0.13 mg·kg-1, respectively. The soil in the study area was mainly weakly acidic, and the contents of the Cd and Hg elements were relatively high compared to the national soil background values and were highly variable. The contents of the Hg and Cd elements in forest land were higher than that in other land uses. The PMF model results showed that the contribution rates of heavy metal pollution sources in the study area were mining sources (37.4%), atmospheric sedimentation sources (7.7%), natural sources (41.1%), and agricultural activity sources (13.8%) and provided suggestions on pollution control measures according to the spatial distribution of the four types of pollution sources. Through the comprehensive assessment of soil environmental geochemistry, the study area was divided into three types of plots, namely, non-risk areas (94.27 km2), accounting for 76.38%; risk-controllable areas (27.45 km2), accounting for 22.24%; and high-risk areas (1.7 km2), accounting for 1.38%. This study provided data support for the prevention and control measures of land pollution in the research area, as well as the delineation of the prevention and control scope.

Evaluation of heavy metal pollution status of Anambra River basin using different indices

Evaluation of heavy metal pollution status of Anambra River basin using different indices

Temporal variation and pollution status of heavy metals in core sediments from Jiangsu intertidal area, China

Eight heavy metal concentrations were analyzed from a 60.35-m-long sediment core in the Jiangsu intertidal area, China. Based on the lithofacies characteristics, mean grain size, downcore distributions of elements, and accelerator mass spectrometry (AMS) 14C and optically stimulated luminescence (OSL) data, the sediments in the core were divided into three units that formed during marine isotope stages 4 (MIS 4), MIS 3, and MIS 1. Except for Cd, all the other heavy metals had the lowest average concentrations in U3, which formed during MIS 4 with the coarsest sediment, representing a fluvial deposit. Most of the heavy metals were positively correlated with Al, Fe, and the total organic carbon (TOC), indicating these metals had the same sources. Pearson's correlation coefficient, enrichment factor, geoaccumulation index, and principal component analysis suggested that there was no element enrichment or contamination in the core sediments and that all heavy metals were naturally sourced.

Heavy Metals Pollution and Other Physicochemical Parameters in the Crude Oil-Impacted Santa Barbara River and Environs, Bayelsa State, Nigeria

Higher levels of heavy metals in aquatic environments are most likely influenced by crude oil spills which may induce significant risk of heavy metal toxicity in aquatic species and humans. This research evaluated the levels of heavy metals and other physicochemical parameters in the crude oil-impacted Santa-Barbara River and environs of Bayelsa State, Nigeria. Heavy metals and other physicochemical parameters were examined using standard methods. Heavy metal pollution status was then deduced with standard pollution indicators. The water and fish samples collected from crude oil-impacted Santa Barbara River were heavily and moderately contaminated with iron, respectively (Igeo index = 4.29 and 2.87 for water and fish, respectively) and highly polluted with examined heavy metals (PLI = 4.29 and 1.13 for water and fish, respectively). The water samples from hand-dug wells were moderately contaminated with iron (Igeo index = 2.87) with overall low pollution by heavy metals (PLI = 0.46), while fish sold in neighboring communities was moderately contaminated with iron (Igeo index = 2.98) with overall moderate pollution by heavy metals (PLI = 0.86). However, potential ecological risks mediated by examining heavy metals in all water and fish samples were generally low (RI < 40). The total dissolved solids, biochemical oxygen demand, nitrate and phosphate concentrations in all water samples were within permissible limits of WHO and FEPA. The ecological risks associated with water and fish from all sampling locations were deduced as low, mainly because iron was the most abundant heavy metal contaminant with no significant toxic response.

Health risk assessment of heavy metals in wild fish and seasonal variation and source identification of heavy metals in sediments: a case study of typical urban river in Xi'an, China.

In order to determine the status of heavy metal pollution in river sediments and wild fish in Xi'an, concentrations of heavy metals (Cr, Ni, Cu, Zn, As, and Pb) were collected and analyzed in sediments and wild fish during dry season (October-November 2020) and wet season (June-July 2021). This study aimed to investigate the spatial and temporal variations of heavy metals in urban rivers of Xi'an, China. Their distribution characteristics and sources as well their pollution levels and health risks were assessed. The findings revealed that influenced by human activities, the heavy metal content in sediments (mg·kg-1 dry weight) in wet season was ranked as follows: Cr (73.09) > Zn (63.73) > Pb (40.31) > Ni (31.52) > Cu (24.86) > As (6.83); in the dry season: Zn (94.07) > Cr (69.59) > Cu (34.24) > Ni (33.60) > Pb (32.87) > As (7.60). Moreover, 32 fish samples from six species indicated an average metal content trend (mg·kg-1 wet weight) of Zn (8.70) > Cr (0.57) > Pb (0.28) > Ni (0.27) > Cu (0.24) > As (0.05). The potential ecological risk indices for sediment heavy metal concentrations in both seasons were well below the thresholds, which indicates that the aquatic environment is in safe level. The analysis of the potential ecological risk of sediment heavy metal concentrations indicates that the aquatic environment is safe for the time being. Based on the estimated daily intake (EDI), target risk quotient (THQ), total target risk quotient (TTHQ), cancer risk (CR), total cancer risk (TCR), and the permissible safety limits set by the agencies, the consumption of the fish examined is safe for human health. However, the presence of Cr and As in wild fish should still be a concern for human health, especially for children. The cumulative effect of heavy metals and the bioconcentration factor (BCF) suggest that sediment and heavy metals in fish are closely related, with higher concentrations in fish living in the bottom layer of the water column than in other water layers, and increasing with increasing predator levels. Correlation analysis and PMF modeling identified and determined four comparable categories of potential sources, namely, (1) atmospheric deposition and traffic sources, (2) agricultural sources, (3) industrial sources, and (4) natural sources.

Prediction of heavy metal ion distribution and Pb and Zn ion concentrations in the tailing pond area.

The pollution caused by tailings ponds has resulted in ecological damage, with soil contamination significantly impacting the daily lives of residents in the vicinity of mining areas and the future development of mining areas. This study assesses the transport status of heavy metal pollution in tailings areas and predicts its impact on future pollution levels. This study focused on lead-zinc tailing ponds, exploring the spatial and chemical distribution characteristics of heavy metals based on the distributions of Pb, Zn, As, Cu, Cr, Cd, Hg, and Ge ions. The concentrations of the major heavy metal ions Pb and Zn in tailings ponds were predicted via the exponential smoothing method. ① The total accumulation of Pb and Zn in the mine tailings ranges from 936.74~1212.61 mg/kg and 1611.85~2191.47 mg/kg, much greater than the total accumulation of the remaining six heavy metals. The total accumulation of associated heavy metal Cu was high, and the lowest total heavy metals were Hg and Ge at only 0.19 mg/kg and 1.05 mg/kg. ② The analyses of soil heavy metal chemical forms reveal that the heavy metals Pb and Zn had the highest exchangeable state content and state ratio and the strongest transport activity in the industrial plaza and village soils. Pb and Zn are the heavy metals with the greatest eco-environmental impacts in the mining area. ③ The predicted results show that the soil concentrations of the heavy metals Pb and Zn around the tailings area in 2026 are 1.335 and 1.191 times the predicted time starting values. The concentrations of the heavy metals Pb and Zn at the starting point of the forecast are already 3.34 and 3.02 times the upper limits of the environmental standard (according to environmental standards for gravelly grey calcium soils). These results have significant implications for heavy metal pollution risk management.

Overview of the Current Research Status and Occurrence Characteristics of Heavy Metal Pollution in Mining Soil

Overview of the Current Research Status and Occurrence Characteristics of Heavy Metal Pollution in Mining Soil

Suspended particulate matter affects the distribution and migration of heavy metals in the Yellow River

Suspended particulate matter (SPM) is an important heavy metal transporter in water. As a well-known high-SPM river, its impact on the distribution and migration of heavy metals in the Yellow River (YR) deserves special attention. In this study, the spatial distributions of heavy metals in surface water and SPM of the YR were investigated. The results indicate that the concentrations (dissolved and particulate phases) and bioavailability (particulate phase) of most heavy metals were higher during the rainy season than during the dry season. A considerable proportion of heavy metals (>70 %) was transported by SPM and fine particles (clay) controlled the pollution status of heavy metals in the YR. This could lead to higher heavy metal concentrations in the SPM midstream and downstream during the rainy season and higher heavy metal concentrations in upstream during the dry season. Heavy metal adsorption experiments showed that specific combination methods (such as binding with carbonate) between Cd and SPM may cause SPM to act as a source of Cd midstream and downstream. This study provides a new perspective on the effects of SPM on heavy metal distribution and migration in the YR.

Spatial-temporal evolution of ecological risks in a typical urban lake in Southwestern China

During urbanization, excessive development and utilization pose varying risks and challenges to the ecosystems of many urban lakes. Sediments are invaluable archives of past ecosystem changes. By analyzing variations in 210Pb and other geochemical indicators in sediment cores, it is possible to assess how susceptible lakes are to the impacts of climate change and human-induced pollution, which is crucial for urban planning and the management of lake environments. This study investigated the status of heavy metal pollution in Lake Longquan, Chengdu City, and reconstructed the historical evolution of its ecological environment using 210Pb dating. Three main conclusions are drawn. (1) Currently, Cd, Cu, Pb, Zn, Cr, and organic matter in the surface sediments of Lake Longquan are highly enriched in the southeastern, central, and northeastern regions. Cd levels even reach 1.54 mg/kg in the southeastern part of the lake near the town. The high overlap of heavy metal distribution with historical aquaculture areas and some tourist areas indicates that aquaculture and tourism are important sources of heavy metals that increase their bioavailability. (2) Lake Longquan is currently at a high potential ecological risk level, and the high potential risk level of Cd may cause ecological safety problems. The biological toxicity of As should be considered, too. (3) The risk evolution in Lake Longquan can be divided into six stages: (i) Before 1977, the ancient river. With the destruction of forest vegetation and the intensification of rock weathering, ecological risks increased. (ii) 1977–1989, construction and development. Due to human factors and the joint influence of heavy precipitation events, ecological risks increased; and (iii) 1989–2010, development prioritized protection. Due to the ineffective implementation of protection policies, aquaculture increases risks. (iv) 2010–2017, development. As a provincial resort and tourism area, the significant increase in human activities has led to constantly rising sedimentation rates and heavy metal concentrations, resulting in an ecological risk peak. (v) 2017–2020, protection. The efficient implementation of lake protection and restoration policies proved to be effective, and the ecological risk started to decrease. (vi) After 2020, protective development. The government's plan to reduce fertilizer usage and increase forest cover will help control ecological risks. It is necessary to continue controlling tourism and aquaculture activities, and transitional areas should be established around lakes for city residents to engage in lakeside sightseeing and recreational sports. This study provides valuable references for controlling and preventing heavy metal pollution in urban lakes.

Human-influenced changes in pollution status and potential risk of sediment heavy metals in Xincun Bay, a typical lagoon of Hainan, China

Pollution status and ecological risks associated with sediment heavy metals (Cu, Pb, Zn, Cd, and Cr) were investigated around Xincun Bay, assessing their spatial variations and relationship with sediment physiochemical factors. Higher concentrations and associated risks were observed in the central region, where mariculture activities were concentrated, compared to non-maricultured areas. Despite with overall low concentrations, Cd had a higher ecological risk. Correlation and principal component analyses revealed similar sources for all metals in Xincun Bay. Heavy metal concentrations varied with expansion of mariculture operations in terms of quantity and scale, confirming the influence of mariculture activities. Sediments around mariculture had higher contents of clay, silt, and total organic carbon (TOC), and finer particle sizes. Quantitative analyses through correlation and linear regression indicated that TOC significantly regulated heavy metal concentration and distribution (p < 0.05). Considering its significant association with TOC, the influence of mean grain size should not be overlooked.

Comprehensive assessment of occurrence, temporal-spatial variations, and ecological risks of heavy metals in Jiaozhou Bay, China: A comprehensive study

Heavy metals play a significant role in marine ecosystems, exerting notable impacts on the environment and human health. In this study, water, sediment, and aquatic organism samples from Jiaozhou Bay were investigated to comprehensively assess the distribution, temporal-spatial variations, and ecological risks of heavy metals. The results indicate that pollution from industrial wastewater discharge contributes to regional differences in the distribution of heavy metals, possibly being a major source of Zn, Cr, Cd, and Hg (r > 0.7, p < 0.05). Biological and physicochemical processes influence the distribution of Zn, Cr, and Pb in the water and sediment. Hg exhibits a polluted state in both the water and sediment, with As and Hg being the two highest-risk heavy metals in water and sediment, respectively. Among the organisms, crustaceans show significantly higher levels of heavy metal content and accumulation compared to mollusks and fish (p < 0.05), and the bioamplification of heavy metals occurs in the sediment-Rapana venosa-Portunus trituberculatus biological pathway. Portunus trituberculatus, Charybdis japonica, Oratosquilla oratoria, and Octopus ocellatus could pose risks to human health, especially for children and vulnerable populations. This study aims to enhance our understanding of the current status of heavy metal pollution in Jiaozhou Bay and to provide a scientific basis and favorable support for the ecological environmental protection and prevention of ecological risks associated with heavy metal pollution in Jiaozhou Bay and other bays in China.

Co-exposure of heavy metals in rice and corn reveals a probabilistic health risk in Guizhou Province, China

The adverse effects of heavy metals have arousing concern in the high geological background area, especially in southwestern Guizhou, China. However, the pollution status of heavy metals are still unclear when exposed to rice and corn in Guizhou province. Therefore, the concentration, pollution level, spatial distribution, and probabilistic health risks of Ni, Cr, Pb, Cu, and Zn are estimated in rice and corn. A total of 241 samples (117 for rice and 124 for corn) were collected from Guizhou province and measured by a method of inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that rice and corn were contaminated with Ni and Cr. High concentrations of Ni were presented in the southeast of rice. It indicated that 22.0 % of rice samples were contaminated with Ni. HI values for children and adults exceeded 1.0 in rice and corn, suggesting that humans might be subject to probabilistic non-carcinogenic risks. FTCR demonstrated that rice and corn might cause probabilistic carcinogenic risks to children and adults, which were both greatly higher than 1.0 × 10−4. Moreover, the contributions of Ni to the HI and FTCR were the highest for adults and children. Therefore, more attention should be paid to the exposure of heavy metals in rice and corn, especially in Ni. The results would provide a novel prospective for pollution control and be helpful for environmental regulation.

A comparative study on the pollution status of heavy metals in soils and sediment from farmlands in Askira Uba, Nigeria

Heavy metals may enter the food chain from soil through mineralization by crops or environmental contamination, as in application of agricultural inputs such as pesticides and fertilizers or in the treatment of soils with sewage sludge cupper content of normal plant tissue. Atomic Absorption Spectroscopic (AAS) method is one of the most commonly used instrument in metal analysis due to its reproducibility of results, short analysis time, lower level of detection. Soil and sediments samples were collected at three distinct stations each, designated as A1, B1, C1 and A2, B2, C2 respectively from Askir/Uba local government area of Borno State, Nigeria. The concentrations of six heavy metals of environmental concern which includes Cd, Cu, Cr, Pb, Ni and Zn were determined by Atomic Absorption Spectrophotometer; Buck scientific model 210GP. The mean concentration of Cd in soil and sediment were (10.7±2.32 mg/kg and 9.62±2.32 mg/kg) and are of toxicological concern. The decrease in concentrations of the metals across sampling locations followed this order Cd &gt; Cu &gt; Cr &gt; Pb &gt; Ni &gt; Zn. The geoaccumulation index of the sediment by each metals are in the following increasing order: B2 &lt; A2 &lt; C2 for Cd and Pb, B2 &lt; C2 &lt; A2 for Cr, A2 &lt; B2 &lt; C2 for Cu, A2 &lt; B2 &lt; C2 for Zn respectively. In general, the order of metal contamination were Zn &lt; Ni &lt; Cu &lt; Pb &lt; Cr &lt; Cd. The results of the findings revealed that the soil and sediment were contaminated with Cadmium, the high level of Cd in the soil were above the recommended values. However, Independent-samples t-test (statically significant at p&lt;0.05) was used to compared the average metal composition in soil and sediment which showed that there was no significant difference on the composition in soil and sediment for all the metals p-value = 0.8939 The aim of the study was to compare the mean level of the soil and sediment with WHO permissible limit, hence evaluate their pollution status by the application of geoaccumulation index.

Determination of geochemical baselines and evaluation of potentially toxic elements in agricultural soils of Ramhormoz Plain, Iran

ABSTRACT The present study was conducted to investigate the heavy metal pollution status of the agricultural soils in Ramhormoz Plain, Khuzestan province, Iran. A total of 54 samples from the depths (0–20 cm) of the soil were collected from the selected areas in (March) 2021. According to the obtained results, the concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Al in soil samples were 1.3, 0.68, 60, 10.6, 0.01, 218, 23, 3.65, 14 and 0.58 mg/kg, respectively, in which As showed significant soil contamination and Cu, Hg, Mn, Ni, Pb, Zn and Al moderate contamination according to the calculation of contamination factor (CF). PCA analysis revealed that both anthropogenic and natural sources of pollution like agricultural and transport activities contributed to the enrichment of study area. Investigation of ecological risk indicated that Ramhormoz Plain was categorized as a high risk area.

Health risk assessment of heavy metal pollution and its sources in agricultural soils near Hongfeng Lake in the mining area of Guizhou Province, China.

Accelerated modern industrial processes, extensive use of pesticides and fertilizers and remaining issues of wastewater irrigation have led to an increasingly severe composite pollution of heavy metals in arable land. Soil contamination can cause significant damage to ecological environments and human health. Mineral resource mining can result in varying degrees of heavy metal pollution in surrounding water systems and soil. As a plateau lake, Hongfeng Lake has a fragile watershed ecosystem. Coupled with the rapid development of the current socio-economy and the ongoing activities of mining, urbanization and agricultural development, the water and soil environment of the lake and arable land are facing serious heavy metal pollution. Therefore, the situation warrants attention. This study focused on characterizing soil types and conducted sampling and laboratory testing on the farmland soil in Hongfeng Lake. The integrated Nemero comprehensive pollution assessment and potential ecological pollution assessment methods were used to evaluate the heavy metal pollution status. The APCS-MLR model was employed to explore the sources of heavy metal pollution. In addition, the human health risk model was used to analyze the association between heavy metal content in cultivated land and human health risks. The single-factor pollution of each element was ranked in descending order: Hg > As > Pb > Cr > Cd, with Hg being the main pollutant factor. The entire area was subjected to mild pollution according to the pollution index. Pollution source analysis indicated two main pollution sources. Hg, As, Pb and Cr pollution mainly resulted from Source 1 (industrial and natural activities), accounting for 71.99%, 51.57%, 67.39% and 68.36%, respectively. Cd pollution was mainly attributed to Source 2 (agricultural pollution source), contributing 84.12%. The health risk assessment model shows that heavy metals posed acceptable carcinogenic risks to humans rather than non-carcinogenic risks. As was the main non-carcinogenic risk factor, while Cr was the main carcinogenic risk factor, with higher risks in children than adults. Our study identified the heavy metal pollution in farmland soil in Hongfeng Lake, evaluated and analyzed the pollution sources and identified the heavy metal elements in cultivated lands that have the greatest impact on human health risks. The aim of this study is to provide a scientific basis for soil heavy metal pollution control.

Research on the Control of Biomass and Heavy Metal Pollution

Faced with the increasing loss of resources and the worsening of environmental pollution, the country is also paying more and more attention to the recycling of resources and pollution control. At present, biomass as a new energy can improve the utilization of resources and environmental conditions. This paper focuses on the basic content of biochar, the status of soil heavy metal pollution and the effect of biochar on the control of heavy metal pollution. Studies have shown that biochar can convert part of exchangeable heavy metals in soil into a stable state through passivation, and the other part of heavy metals can be absorbed by plants to achieve the purpose of repairing soil plants, thereby indirectly improving soil characteristics. In addition, biochar can also use chemical leaching method to remove heavy metal pollutants in soil by leaching solution to improve soil heavy metal pollution. In order to better optimize the use of resources and improve environmental pollution, we should explore the interaction between biomass energy and environmental media more deeply, and innovate the technologies and methods of birth matter energy in pollution control. The combination of biomass and heavy metal pollution control can not only promote more in-depth research on biomass properties, but also make great contributions to human resource recovery and environmental pollution control.

Source and pollution assessment of heavy metals in surface sediments of Laoshan Bay, South Yellow Sea, China

A total of 25 surface sediment samples collected from Laoshan Bay, China, during 2018, were analyzed for heavy metal concentrations, sources, and pollution status. The Cu, Zn, and Cr distributions were similar, whereas the distributions of other metals and the total organic carbon (TOC) content were irregular, and high concentrations appeared in one or two areas. Pearson's correlation coefficient, the geoaccumulation index, and principal component analysis were used to distinguish the sources and assess the pollution risk of heavy metals. The results showed that the surface sediments in Laoshan Bay were not polluted by Cu, Zn, Cr, or As, but were unpolluted to strongly polluted with Pb, Cd, and Hg. Cu, Zn, Cr, and As were mainly derived from natural sources; Pb and Cd were mainly derived from anthropogenic sources; and Hg may have had compound sources.

Source Apportionment and Potential Ecological Risk Assessment of Soil Heavy Metals in Typical Industrial and Mining Towns in North China

To understand the status of heavy metals in soils of typical industrial and mining towns and quantitatively analyze the potential sources, the contents of seven heavy metals (Cd, As, Pb, Cr, Cu, Ni, and Zn) in 150 surface soils in Xuanhua District, Zhangjiakou City, Hebei Province were collected and examined. The geoaccumulation index and potential ecological risk index methods were used to evaluate the heavy metal pollution status and potential ecological risk. Principal component analysis (PCA) and the positive matrix factorization (PMF) model were used to comprehensively analyze the pollution sources of seven heavy metals, and geostatistics was used to identify the high contribution areas of potential sources. The results revealed that:① the average values of heavy metals in the study area ranged from 0.23-103.34 mg·kg-1, among which the average contents of Cd, Pb, Cu, and Zn were higher than the soil background value of Hebei Province. ② The results of the geoaccumulation and potential ecological risk indices demonstrated that the degree of pollution of the seven heavy metals was in the following order:Cd>Pb>Cu>Zn>Ni>As>Cr, the content of Cd in 16% sites was above a moderate pollution level, and the potential ecological risk of heavy metals in more than 95% sites was at a light risk level. ③ The main sources of accumulation of the seven heavy metals in the study area were combined sources of industry and traffic, natural sources, and agricultural sources, with their contribution rates of 33.1%, 48.7%, and 18.2%, respectively. Among them, Cd, Pb, Cu, and Zn were primarily affected by the combined sources of industry and transportation; Cr, Ni, and As were mainly affected by natural sources, whereas Cd and some As were affected by agricultural sources. The organic combination of PCA, PMF model, and geostatistical methods confirmed the results of each analysis, which increased the reliability of the analytical results of heavy metal sources.

Prioritized regional management for antibiotics and heavy metals in animal manure across China

High levels of antibiotics and heavy metals in animal manure pose a potential threat to both the ecological environment and public health. A regional knowledge of their distribution and risk assessment across China remains unclear. A dataset containing 4082 records covering a total of forty-two antibiotics and eight heavy metals was established for animal manure across China. The results showed that the residual concentration of antibiotics was in the order of tetracyclines > aminoglycosides > fluoroquinolones > macrolides > sulfonamides > β-lactams, and that of heavy metals is Zn > Cu > Cr > Pb > Ni > As > Cd > Hg. The mean concentration of antibiotics and heavy metals was higher in pig manure compared to chicken and cow manure (Kruskal-Wallis test). The lowest level of antibiotics was observed in Northwest China based on geographic distribution characteristics. It was related to the high ratio of cow and sheep farming that less antibiotics were administered to. The pollution status of heavy metals was more severe in East China. Furthermore, high correlations were observed between antibiotics (tetracyclines) and heavy metals (Cu, Zn, and As). Especially, tetracycline in North China and Cd in Northeast China exhibited a high risk in manure; thus, they were priority regions for antibiotics/heavy metals pollution control. This study identified risk assessment of typical antibiotics and heavy metals in animal manure and emphasized the necessity of regional management across China.

Heavy metal levels in the dairy production chain in China

AbstractThe aims of this study were to investigate the heavy metal pollution status and distribution and to analyze the relationships among metal concentrations of different links in the dairy production chain. Chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) levels in water, fodder, milk, blood, hair, and feces samples collected from cows from five dairy farms in China were measured. The concentrations of Cr, As, Cd, Pb, Cu, and Zn were 4.61–11.11, 0.06–0.46, 0.17–0.29, 2.84–4.23, 4.11–7.72, and 7.23–19.91 mg/kg in silage; 12.72–40.85, 0.76–2.40, 0.05–0.16, 4.73–9.16, 44.14–78.46, and 4148.51–4845.20 μg/L in milk; 33.59–60.73, 0.09–3.57, 0.29–1.78, 20.14–39.20, 821.34–1007.45, and 2665.10–4929.95 μg/L in blood; 0.59–1.06, 0.02–0.09, 0.08–0.11, 1.70–2.09, 6.45–8.64, and 9.73–1.56 mg/kg in hair; 31.75–296.35, 0.33–5.96, 0.18–0.53, 3.35–9.06, 12.27–41.39, and 56.54–196.34 mg/kg in feces, respectively. The concentrations of heavy metals in hair were higher than those in the other samples and when combined with the results from the silage and tissue samples, we can assume that cow's hair can be used as a biological indicator for heavy metal contamination in the dairy production chain.