Contamination assessment,source apportionment and associated health risks of PTEs in agricultural soil under five land-use patterns in Sanya,China

To understand the levels of potentially toxic elements(PTEs)contamination in soils and their effects on human health from different agricultural land use in Sanya,China.128 soil samples(64 topsoil samples and corresponding subsoil samples)were collected from the five representative land-use patterns.Inductively coupled plasma mass spectrometry(ICP-MS),Atomic fluorescence spectrometry(AFS),and Inductively coupled plasma optical emission spectrometry(ICP-OES)were used to determine the content of PTEs(As,Cd,Hg,Cu,Cr,Ni,Pb,Zn,Co,Mo,Sb,and V).Correlation analysis and factor analysis were used to determine the source of PTEs.Geo-accumulation index(I_(geo)),hazard quotient(HQ),and total carcinogenic risk index(TR)were used to measure the PTEs contamination and its relative health impacts.Results showed that the average values of 12 PTEs in topsoil were higher than the Hainan soil geochemical baseline,showing different degrees of PTEs accumulation effect.The concentration of PTEs in the topsoil was lower than those in the subsoil except for Cd and Hg.The I_(geo)revealed that the major accumulated element in soils was As followed by Mo.Source apportionment suggested that parent materials and agricultural practices were the dominant factors for PTEs accumulation in the topsoil.Noncarcinogenic risks of soil samples from five land-use patterns presented a trend of paddy field>dry field>woodland>orchard>garden plot.However,the HQ values of 12 PTEs were less than the recommended limit of HQ=1,representing that there are no non-carcinogenic risks of PTEs for children and adults in the study area.The TR values are within 6.95×10^(-6)-1.38×10^(-5),which corresponds to the low level.Therefore the PTEs in the agricultural soil of the study area show little influence on the health status of the local population.

Human Health Risks from Exposure to Heavy Metals of Suspended Particulate Matter around the Tongon Gold Mine, Côte d’Ivoire

The Tongon mine, the largest gold mine in C?te d’Ivoire, has been in operation since April 2010. However, to our knowledge to date, no study has been conducted on metallic contamination in suspended particulate matter (PM10 and PM2.5) where there is a lack of information on the carcinogenic and non-carcinogenic risk to human health associated with the exposure of populations in the Tongon area to these pollutants. The general objective of this study is to evaluate the level of contamination of PM10;PM2.5 by heavy metals and their impact on the health of populations exposed to these pollutants in the Tongon gold mine area. The sampling and measurement of suspended particulate matter (PM10 and PM2.5) were done using a MiniVol TAS passive air sampler. Heavy metal concentrations were determined by inductively coupled plasma mass spectroscopy (Nex ION 2000 ICP-MS, USA). The results indicate that the average concentrations of suspended particles (PM2.5 and PM10) obtained are all above the recommended exposure limits. In addition, among the heavy metals contained in the suspended particles, the concentrations of arsenic and nickel are high and all above the standard limit values. The assessment of the health risks related to the inhalation of PM10 particles reveals that their inhalation over a long period could cause a carcinogenic risk.

MUTAGENICITY AND CARCINOGENICITY OF FISH SAUCE FROM A COUNTY WITH THE HIGH RISK FOR GASTRIC CANCER IN CHINA

The mutagenicity and carcinogenicity of fish sauce (FS) sample from Changle County, a high gastric cancer mortality (113.20/105) area, were investigated with the biologic short-term tests and laboratory animal experiment. The results showed that the extract of FS was markedly direct mutagenic toward S. typhimurium TA100, induced high sister chromatid exchanges (SCE) and micronucleus (MN) in V79 cells after nitrosation with sodium nitrite. But the non-nitrosated FS did not. The nitrosated fish sauce (NFS) also induced SOS in E. coli PQ37 and alkylation of calfthymus DNA. The potency of NFS to induce unscheduled DNA synthesis (UDS) in human normal gastric mucosal cells was increased about fivefold compared with FS. When the NFS extract was given to newborn rats by gavage, dys-plasia and adenocaroinoma were induced in the glandular stomach in the 4th and 16th experimental week, respectively. N-nitrosamides were also found in NFS, which may account for the mutagenicity and carcinogenicity of NFS. It is indicated that FS, a traditional daily eaten seasoning, may contribute to the causes of the high gastric cancer mortality for the local residents.

Heavy Metals in Native Potato and Health Risk Assessment in Highland Andean Zones of Junín, Peru

Heavy metals are transferred from the abiotic environment to living organisms, accumulate in food, contaminate the food chain, and are an important route of human exposure involving a potential health risk. In this study, the concentrations of heavy metals (Cd, Fe, Pb, Zn and As) in agricultural soils and tubers of Solanum tuberosum spp. andigena (native potato) were evaluated. Also, an assessment of the health risk associated with the daily intake by the local population was performed in the four districts of the department of Junín, between altitudes of 3800 m to 4200 m. The heavy metals concentrations in soils with native potato cultivation followed the following decreasing order of Fe > Zn > Pb > As > Cd, with values below national standards. The heavy metals content in native potatoes was below the limits recommended by international standards with the exception of Pb. The bioconcentration factor (BCF) for the two native potato varieties in decreasing order was Zn > Cd > Pb > As > Fe, all less than 0.5. The estimated daily intake of metals (EDIM) in adults and children through the consumption of native potatoes was higher for Fe and Zn. The threshold carcinogenic risk values (TCR) for As exceeded the safety limits 1 × 10-4. It is concluded that the residents in the four high Andean localities would be exposed to carcinogenic adverse health effects associated with the intake of native potatoes. It is important to monitor the concentration of As and other heavy metals in the Andean soils and crops in order to implement a soil and crop management program to ensure food quality.

Geochemical signatures and human health risk evaluation of rare earth elements in soils and plants of the northeastern Qinghai-Tibet Plateau,China

Information on rare earth elements(REEs)in soils and plants of the Qinghai-Tibet Plateau is very limited.Therefore,in this study,we performed field sampling to explore the geochemical signatures and human health risk of REEs in soils and plants of the northeastern Qinghai-Tibet Plateau,China.A total of 127 soil samples and 127 plant samples were collected from the northeastern Qinghai-Tibet Plateau to acquire the geochemical signatures and related human health risks of REEs.The mean total concentrations of REEs in soils and plants of the study area reached 178.55 and 10.06 mg/kg,respectively.The light REEs in soils and plants accounted for 76%and 77%of the total REEs,respectively.REEs showed significantly homogenous distribution in soils but inhomogeneous distribution in plants of the study area.Characteristic parameters indicated that light REEs were enriched and fractionated significantly,while heavy REEs were moderately fractionated in soils and plants.REEs in soils and plants showed significantly negative Europium anomaly.Cerium showed slightly positive anomaly in plants and slight anomaly in soils.The normalized distribution patterns of REEs were generally similar in the analyzed soils and the corresponding plants of the study area.The average bio-concentration factor of REEs ranged from 0.0478(Scandium)to 0.0604(Europium),confirming a small accumulation of REEs by plants.Health risks caused by REEs in soils and plants were negligible,while risks for adults were lower than those for children.This study provides important information on REEs in soils and plants of the northeastern Qinghai-Tibet Plateau.

Degradation and Exposure Risk Assessment of Six Sulfonylurea Herbicides in Soil

[Objective] The paper was to understand the degradation tendency and carcinogenic risks of six sulfonylurea herbicides in soil, and guide the safe use. [Method] The herbicide residues were determined by UPLC-MS/MS and the degradation rates were calculated. In addition, the changing tendencies of directly exposed carcinogenic risk along with the herbicide residues were analyzed through the risk evaluation model. [Result] Significant differences were found among the degradation tendencies of the six sulfonylurea herbicides in soil, the longest theoretical half-life was 28.9 d and the shortest was 18.7 d. After application, the maximum carcinogenic risk value of the six herbicide residues in soil was 2.5×10^-8, lower than the reference value （×10^-6）. Oral intake and dermal contact were the major exposure routes, with the total contribution rate of 99.78% to the carcinogenic risk by direct exposure. When the P-value was less than 0.01, both original residue level and carcinogenic risk were significantly correlated with the dosage of herbicide, and the correlation coefficient was 0.983 1. [Conclusion] Under the condition of test, it does not have any unacceptable carcinogenic risk to human body. Moreover, selection of readily degradable herbicide with low residue level, and control of application rate are the effective approaches of reducing the carcinogenic risk of direct exposure.

Pitfalls in Assessing Risks from Carcinogens

The decision to classify a chemical as a human carcinogen must depend upon agreed conclusions from epidemiology, bioassays, and some short-term corroborating tests; information from only one of these disciplines is inadequate. Most pitfalls appear in interpreting the results from animal bioassays; this report will concentrate on them. Often the conclusion is accepted that a chemical is an animal carcinogen without a critical appraisal of the experimental design. By manipulating the experiment, 90 + % of all chemicals can induce some tumor in a rodent. Pitfalls encountered in bioassays result from not specifying the exact agent under test and how it relates to human exposure, using inappropriate routes of administration unrelated to humans, administering illogically high doses, or concluding that a cancer was induced without adequate histopathological description of the lesion. Importance of animal husbandry is often overlooked. Pitfalls are also related to short-term tests. Finally, a major pitfall in assessing carcinogenic risk from chemicals is drawing global conclusions about the carcinogenicity of an agent after the detection of only one or two tumors in the treated group.

Non-Genotoxic Carcinogens.Approaches to Their Risk Assessment

Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

New development in risk assessment of genotoxic carcinogens in foods

The no-observed-effect level (NOEL) in a study of carcinogenicity for compounds that are both genotoxic and carcinogenic represents the limit of detection in that bioassay, rather than an estimate of a possible threshold. Therefore, for those genotoxic and carcinogenic contaminants (e.g. acrylamides, PAHs, etc.) in foods it is not possible to develop health-based guidance values (e.g. ADI or PTWI) using the traditional NOEL and safety/uncertainty factors.

Current cancer situation in China:good or bad news from the 2018 Global Cancer Statistics?

Cancer is the leading cause of death in China and depicting the cancer pattern of China would provide basic knowhows on how to tackle it more effectively.In this study we have reviewed several reports of cancer burden,including the Global cancer statistics 2018 and Cancer statistics in China,2015,along with the GLOBCAN 2018 online database,to investigate the differences of cancer patterns between China,the United States(USA)and the United Kingdom(UK).An estimated 4.3 million new cancer cases and 2.9 million new cancer deaths occurred in China in 2018.Compared to the USA and UK,China has lower cancer incidence but a 30%and 40%higher cancer mortality than the UK and USA,among which 36.4%of the cancer-related deaths were from the digestive tract cancers(stomach,liver,and esophagus cancer)and have relatively poorer prognoses.In comparison,the digestive cancer deaths only took up≤5%of the total cancer deaths in either USA or UK.Other reasons for the higher mortality in China may be the low rate of early-stage cancers at diagnosis and non-uniformed clinical cancer treatment strategies performed by different regions.China is undergoing the cancer transition stage where the cancer spectrum is changing from developing country to developed country,with a rapidly increase cancer burden of colorectal,prostate,female breast cancers in addition to a high occurrence of infection-related and digestive cancers.The incidence of westernized lifestyle-related cancers in China(i.e.colorectal cancer,prostate,bladder cancer)has risen but the incidence of the digestive cancers has decreased from 2000 to 2011.An estimated 40%of the risk factors can be attributed to environmental and lifestyle factors either in China or other developed countries.Tobacco smoking is the single most important carcinogenic risk factor in China,contributing to~24.5%of cancers in males.Chronic infection is another important preventable cancer contributor which is responsible for~17%of cancers.Comprehensive prevention and control strategies in China should include effective tobacco-control policy,recommendations for healthier lifestyles,along with enlarg-ing the coverage of effective screening,educating,and vaccination programs to better sensitize greater awareness control to the general public.