Assessment of Heavy Metal Pollution in Topsoil around Beijing Metropolis

Assessment of Contents and Health Impacts of Four Metals in Chongming Asparagus-Geographical and Seasonal Aspects

In this paper, the contents of four typical metals (Pb, Cd, Hg, and As) in asparagus, water, and soil from Chongming Island were quantitatively determined by inductively coupled plasma mass spectrometry (ICP-MS). The contents of these metals in asparagus showed a common rule of Pb > As > Cd > Hg in different harvest seasons and regions. Significant seasonal differences were found in the contents by difference analysis, but no obvious regional differences were observed. Furthermore, the asparagus did not accumulate these four metals from the soil in Chongming Island by the assessment of bio-concentration factor. The asparagus was proved safe by the analysis of single-factor pollution index and Nemerow pollution index. Through combining the analysis of the above indexes and the geological accumulation index, we found that 51.62% of soil samples were mildly polluted by cadmium. The results of health risk analysis showed that the risk value of children was higher than that of adults under oral exposure, but the four metals in asparagus possessed no obvious risk to health. The above assessments illustrate that the daily consumption of asparagus in Chongming Island will not cause potential health impacts. It is of benefit to ensure the quality and economic interests of asparagus planting in Chongming Island through the investigation of this study.

Risk assessment and ecotoxicological diagnosis of soil from a chemical industry park in Nanjing, China

Soil pollution due to the activities of industrial parks, is becoming an increasingly serious issue, particularly throughout China. Therefore, it is essential to explore the soil pollution characteristics and its ecotoxicological effects on model species, such as higher plant species, in typical industrial areas. In this study, concentrations of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were examined in the soil collected from 10 sampling sites at a chemical industry park in Nanjing, China. The pollution index was used to assess the heavy metal pollution level of soils, while the hazard index (HI) and carcinogenic risk index (RI) were calculated to assess the human health risk of soil PAHs. In addition, wheat (Triticum aestivum L.) was used as the model species to evaluate the ecotoxicological effects of polluted soil in pot experiments. Results showed that the content of heavy metals and PAHs varied greatly in soil samples, among which the heavy metal pollution at S1, S2 and S3 was the most serious. The health risk assessment of PAHs indicated that non-carcinogenic and carcinogenic values for all soil samples were below the threshold levels. Statistical analysis of the correlation between contaminated soil and toxic effects in wheat found that the significance values of regression equations were all less than 0.05 for chlorophyll content, peroxidase (POD) and amylase (AMS) activity. This indicates that the chlorophyll content, POD and AMS activity in wheat leaves could be suitable biomarkers for evaluation of the combined toxicity of multiple pollutants. This study provides a reference for future research on the risk assessment of soil containing multiple pollutants from industrial chemical parks.

Detection, Distribution and Health Risk Assessment of Toxic Heavy Metals/Metalloids, Arsenic, Cadmium, and Lead in Goat Carcasses Processed for Human Consumption in South-Eastern Nigeria

Notwithstanding the increased toxic heavy metals/metalloids (THMs) accumulation in (edible) organs owed to goat′s feeding habit and anthropogenic activities, the chevon remains increasingly relished as a special delicacy in Nigeria. Specific to the South-Eastern region, however, there is paucity of relevant data regarding the prevalence of THMs in goat carcasses processed for human consumption. This work was, therefore, aimed to investigate the detection, distribution and health risk assessment of THMs in goat carcass processed for human consumption in South-Eastern Nigeria. To achieve this, a total of 450 meat samples (kidney, liver and muscle) were evaluated from 150 randomly selected goat carcasses processed in two major slaughterhouses in Enugu State. The detection, distribution, as well as health risk assessment parameters followed standard procedures. Results revealed that at least one THM was detected in 56% of the carcasses. Mean concentrations of arsenic (As) were 0.53 ± 0.10 mg/kg, 0.57 ± 0.09 mg/kg and 0.45 ± 0.08 mg/kg, lead (Pb) were 0.48 ± 0.38 mg/kg, 0.45 ± 0.24 mg/kg and 0.82 ± 0.39 mg/kg, cadmium (Cd) was 0.06 ± 0.32 mg/kg, 0.02 ± 0.00 mg/kg, and 0.02 ± 0.00 mg/kg for kidney, liver and muscle tissues, respectively. The estimated daily intakes (EDI) for all THMs were above the recommended safe limits. The target hazard quotient (THQ) and hazard index (HI) computed for all As, Cd and Pb fell below unity in all the studied organs, which indicated no non-carcinogenic risks. Curtailing the anthropogenic activities that aid the THM-contamination in goat production/processing lines is recommended. Screening for THM-contamination in Nigerian slaughterhouses is imperative, so as to ascertain the toxicological safety of meats intended for human consumption.

High Doses of Copper and Mercury Changed Cecal Microbiota in Female Mice

The aim of the present study was to investigate the effects of high doses of copper (Cu) and mercury (Hg) on the cecal microbiota in female mice. Forty-eight Kunming mice were randomly divided into the control group (CCk group), the Cu group (CCu group), the Hg group (CHg group), and the Cu + Hg group (CCH group). At the 90th day, cecal tissues were prepared for histopathological analysis and cecal contents for analysis by 16S rRNA sequencing method. Cecal tissues from treatment groups had histopathological lesions including increased thickness of inner muscularis and outer muscularis, widened submucosa, decreased goblet cells, mild to moderate necrosis of enterocytes, blunting of intestinal villi, and severe atrophy of central lacteal. Furthermore, compared to the CCk group, the abundance of bacteria genera Rikenella, Jeotgailcoccus, and Staphylococcus were significantly decreased, whereas the bacteria genus Corynebacterium was significantly increased in the CCu group. The abundance of bacteria genera of Sporosarcina, Jeotgailcoccus, and Staphylococcus were significantly decreased in the CHg group and CCH group. The bacteria genus Anaeroplasma was significantly increased in the CCH group. The results indicated that high doses of Cu and Hg caused histopathological lesions and changed the diversity of microbiota in the cecum of female mice, which provide a theoretical basis for more accurate assessment of the risk in intestinal diseases caused by Cu and Hg.

Spatial heterogeneity of heavy metal contamination in soils and plants in Hefei, China

The contamination of soil and plants with heavy metals, which has detrimental influences on plant growth, water purification, and food safety, has emerged as a serious global issue. To better understand the spatial variations of contamination of heavy metals associated city development and land use types, we collected soil samples and Magnolia grandiflora branches to quantify lead (Pb) and cadmium (Cd) contents of the roadside, industrial, residential, and park greenbelts in Hefei City, China. We found that Pb content in soil was the highest in roadside greenbelts and the lowest in parks with industrial and residential greenbelts being intermediate, while Cd in soil was the highest in greenbelts close to city center and decreased with the distance to city center. Pb in M. grandiflora, however, did not differ among greenbelt types but decreased with distance to the city center. Cd in M. grandiflora was the highest in roadside and lowest in parks and also decreased with the distance to the city center. Across all greenbelt types and the distances to the city center, Pb and Cd contents were positively correlated in soil and plants. Our findings suggest that vehicle traffic, population density, and age of urbanization collectively contribute to soil and plant contamination of Pb and Cd.

Energy Dispersive X-ray (EDX) microanalysis: A powerful tool in biomedical research and diagnosis

The Energy Dispersive X-ray (EDX) microanalysis is a technique of elemental analysis associated to electron microscopy based on the generation of characteristic Xrays that reveals the presence of elements present in the specimens. The EDX microanalysis is used in different biomedical fields by many researchers and clinicians. Nevertheless, most of the scientific community is not fully aware of its possible applications. The spectrum of EDX microanalysis contains both semi-qualitative and semi-quantitative information. EDX technique is made useful in the study of drugs, such as in the study of drugs delivery in which the EDX is an important tool to detect nanoparticles (generally, used to improve the therapeutic performance of some chemotherapeutic agents). EDX is also used in the study of environmental pollution and in the characterization of mineral bioaccumulated in the tissues. In conclusion, the EDX can be considered as a useful tool in all works that require element determination, endogenous or exogenous, in the tissue, cell or any other sample.

Review of the Spatial Distribution, Source and Extent of Heavy Metal Pollution of Soil in China: Impacts and Mitigation Approaches

BACKGROUND

China has undergone a rapid industrial revolution and urbanization during the past three decades. This expansion is largely responsible for the release of a large amount of heavy metals into soils and is increasingly raising concerns over the potential effects on human health and the environment. The problem is drawing increasing attention, especially after an extensive nationwide soil survey report in 2014. A number of studies have examined soil contamination by heavy metals in China. However, most of these studies have been small in scale and it is therefore challenging to get a general overview of the level of contamination across the entire country.

OBJECTIVES

The present study is aimed at presenting a synthesized overview of the extent, pattern, and impact of heavy metal contamination of soils in China, including mitigation approaches.

METHODS

Eighty-six journal articles and other literature such as reports, internet sources, and statistical yearbooks were narratively and critically synthesized to compile a holistic summary of sources of heavy metals, the extent of pollution, spatial distribution and impact of heavy metal contamination in China. The major findings from these studies are presented, along with mitigation approaches applicable to China.

DISCUSSION

A synthesis of major findings from recent scientific journals shows that about 10.18% of farmland soils which supports 13.86% of grain production in China is affected by heavy metals. The main sources of pollution are anthropogenic activities. Even though the spatial distribution of pollution is highly variable owing to natural and human factors, provinces with intensive industrial activities such as Henan, Shandong, and Sichuan are more highly polluted than others. These regions are top grain producing areas and hence require close follow-up for development of feasible approaches to mitigating crop contamination and associated health risks emerging in parts of China. The government recently launched a program aimed at determining sound reclamation strategies.

CONCLUSION

Mitigation of heavy metal contamination in China requires coordination of different actors and integration of all feasible reclamation approaches.

COMPETING INTERESTS

The authors declare no competing financial interests.

Assessing Lead, Nickel, and Zinc Pollution in Topsoil from a Historic Shooting Range Rehabilitated into a Public Urban Park

Soil contamination is a persistent problem in the world. The redevelopment of a site with a historical deposition of metals might conceal the threat of remaining pollution, especially when the site has become a public place. In this study, human health risk assessment is performed after defining the concentrations of Pb, Ni, and Zn in the topsoil of a former shooting range rehabilitated into a public park in the Municipality of Kesariani (Athens, Greece). A methodology that uses inductively coupled plasma mass spectrometry (ICP-MS, 13 samples), another that uses portable X-ray fluorescence (XRF) following a dense sample design (91 samples), and a hybrid approach that combines both, were used to obtain the concentrations of the trace elements. The enrichment factor and geoacummulation index were calculated to define the degree of pollution of the site. The hazard quotient and cancer risk indicators were also computed to find the risk to which the population is exposed. The present study reveals high non-carcinogenic health risk due to Pb pollution with ingestion as the main exposure pathway. The carcinogenic risk for Pb is within tolerable limits, but the definition of land use might alter such a statement. Lastly, regarding Ni and Zn, the site is unpolluted and there is insignificant carcinogenic and non-carcinogenic risks.