Exploring the Relationship between Ecosystem Services under Different Socio-Economic Driving Degrees.

The large-scale transformation of natural ecosystems to socio-economic development land types under human activities was a primary reason for the decline of regional ecosystem services. It is a key issue for regional ecosystem planning and management to reveal the relationship between ecosystem services of different land use types under different socio-economic driving degrees. However, the current related research was not in-depth. Based on the land use data of Wuhan City in 1980, 1990, 2000, 2010, and 2020, this study classified land use into three categories according to the different degrees of human activities on natural ecosystem development: the land use of a natural ecosystem (LUNE), the land use of a productive ecosystem (LUPE), and the land use of a socio-economic system (LUSE). The InVEST model was used to simulate five ecosystem services (grain yield, water yield, carbon storage, habitat quality, and water purification), and the spatio-temporal distribution and functional transformation of the three land use types were analyzed. Results showed that with the intensified urban expansion in Wuhan, the LUSE types increased to 2.7 times that of the original. However, the natural land types basically maintained a stable area, coupling with the large-scale transformation between the LUPE and LUSE types. Land use change resulted in significant spatial changes of five ecosystem services, especially carbon storage and habitat quality. The correlation analysis indicated that the five kinds of ecosystem services mainly showed a synergistic relationship, meanwhile the LUSE type denoted the most significant correlation with ecosystem services among these three category types. This study indicated that besides the protection of natural ecosystems, the LUSE type would become the key land use type in the planning and management of improving regional ecological function.

6:2 Chlorinated polyfluoroalkyl ether sulfonate as perfluorooctanesulfonate alternative in the electroplating industry and the receiving environment.

Electroplating industry is an important application field of per- and polyfluoroalkyl substances (PFASs) as the chromium mist suppressants. 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFAES) and perfluorooctanesulfonate (PFOS) have been the two widely used mist suppressants, and after the ban of PFOS, 6:2 Cl-PFAES will become the dominant suppressant. The behavior and mechanisms of 6:2 Cl-PFAES in the electroplating industry and the receiving environment were studied and compared with PFOS. 6:2 Cl-PFAES behaved similarly with PFOS due to their similar chemical structure. However, some difference exists for the relatively stronger hydrophobicity of 6:2 Cl-PFAES. Up to 35.7 mg/L of PFOS and 13.4 mg/L of 6:2 Cl-PFAES were found in the industrial wastewater influents, and were effectively reduced to 0.3-0.8 mg/L by the interaction with chromium hydroxide through hydrophobic interaction and ligand exchange. The stronger hydrophobicity of 6:2 Cl-PFAES than PFOS resulted in its accumulation in the surface of foams and comparable or less removal during the industrial and municipal wastewater treatment. 6:2 Cl-PFAES exhibited higher bioaccumulation potential than PFOS in the surface water. 6:2 Cl-PFAES emitted by both mists and water may pose health risks to humans. More attentions towards 6:2 Cl-PFAES are needed after the replacement of PFOS by it in the electroplating industry as a global contaminant of emerging concerns.

Investigation and risk assessment of dibutyl phthalate in a typical region by a high-throughput dual-signal immunoassay.

The systematic investigation and risk assessment of dibutyl phthalate (DBP) were performed using an ultrasensitive dual-signal immunoassay in Zhenjiang, Jiangsu Province. In this study, C-dots@H-MnO2 nanohybrid were synthesized and labelled on the secondary antibody to generate fluorometric and colorimetric signals. Attributed to the efficient catalysis of carbon dots (C-dots) and the high C-dots loading of hollow manganese (IV) oxide (H-MnO2), the excellent sensitivity and low detection limits (0.243 and 0.692 µg/L respectively) were produced. Based on the proposed method, 25 water and 119 beverage samples were investigated. DBP was found in all water samples and 65.5% of beverage samples, with the concentrations varying in 16.5-32.1 µg/L and 0-553 µg/L, respectively. In addition, the mean concentration (22.9 µg/L) in waters was decreased significantly compared with that detected in 2016 (43.5 µg/L) by our Lab. For beverages, a similar phenomenon was observed by the measured concentrations from coffee. Furthermore, the potential ecological risks of DBP were evaluated, the results indicated that human activities had caused serious pollution and high risks to the local aquatic ecosystem. On the other hand, the results of health risk assessment suggested that DBP in beverages might not cause obvious side effects to local residents.

One-pot molten salt method for constructing CdS/C3N4 nanojunctions with highly enhanced photocatalytic performance for hydrogen evolution reaction.

The construction of heterojunction photocatalysts for efficiently utilizing solar energy has attracted considerable attention to solve the energy crisis and reduce environmental pollution. In this study, we use the energy released from an easily-occurred exothermic chemical reaction to serve as the drive force to trigger the formation of CdS and C3N4 nanocomposites which are successfully fabricated with cadmium nitrate and thiourea without addition of any solvents and protection of inert gas at initial temperature, a little higher than the melting point of thiourea. The as-prepared CdS/C3N4 materials exhibit high efficiency for photocatalytic hydrogen evolution reaction (HER) with the HER rate as high as 15,866 µmol/(g∙hr) under visible light irradiation (λ > 420 nm), which is 89 and 9 times those of pristine C3N4 and CdS, respectively. Also, the apparent quantum efficiency (AQE) of CdS/C3N4-1:2-200-2 (CdS/C3N4-1:2-200-2 means the ratio of Cd to S is 1:2 and the reaction temperature is set at 200°C for two hours) reaches 3.25% at λ = 420 ± 15 nm. After irradiated for more than 24 hr, the HER efficiencies of CdS/C3N4 do not exhibit any attenuation. The DFT calculation suggests that the charge difference causes an internal electric field from C3N4 pointing to CdS, which can more effectively promote the transfer of photogenerated electrons from CdS to C3N4. Therefore, most HER should occur on C3N4 surface where photogenerated electrons accumulate, which largely protects CdS from photo-corrosion.

Occurrence, profiles, and ecotoxicity of poly- and perfluoroalkyl substances and their alternatives in global apex predators: A critical review.

Certain poly- and perfluoroalkyl substances (PFASs) exhibit significant bioaccumulation/biomagnification behaviors in ecosystems. PFASs, such as perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS) and related precursors, have elicited attention from both public and national regulatory agencies, which has resulted in worldwide restrictions on their production and use. Apex predators occupy the top trophic positions in ecosystems and are most affected by the biomagnification behavior of PFASs. Meanwhile, the long lifespans of apex predators also lead to the high body burden of PFASs. The high body burden of PFASs might be linked to adverse health effects and even pose a potential threat to their reproduction. As seen in previous reviews of PFASs, knowledge is lacking between the current stage of the PFAS body burden and related effects in apex predators. This review summarized PFAS occurrence in global apex predators, including information on the geographic distribution, levels, profiles, and tissue distribution, and discussed the trophic transfer and ecotoxicity of PFASs. In the case where legacy PFASs were restricted under international convention, the occurrence of novel PFASs, such as 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and perfluoroethylcyclohexane sulfonate (PFECHS), in apex predators arose as an emerging issue. Future studies should develop an effective analytical method and focus on the toxicity and trophic transfer behavior of novel PFASs.

Current progress on catalytic oxidation of toluene: a review.

Toluene is one of the pollutants that are dangerous to the environment and human health and has been sorted into priority pollutants; hence, the control of its emission is necessary. Due to severe problems caused by toluene, different techniques for the abatement of toluene have been developed. Catalytic oxidation is one of the promising methods and effective technologies for toluene degradation as it oxidizes it to CO2 and does not deliver other pollutants to the environment. This paper highlights the recent progressive advancement of the catalysts for toluene oxidation. Five categories of catalysts, including noble metal catalysts, transition metal catalysts, perovskite catalysts, metal-organic frameworks (MOFs)-based catalysts, and spinel catalysts reported in the past half a decade (2015-2020), are reviewed. Various factors that influence their catalytic activities, such as morphology and structure, preparation methods, specific surface area, relative humidity, and coke formation, are discussed. Furthermore, the reaction mechanisms and kinetics for catalytic oxidation of toluene are also discussed.

Rapid heavy metal sensing platform: A case of triple signal amplification strategy for the sensitive detection of serum copper.

Heavy metals are considered as hazardous substances to human because of their toxicity, persistence and bioaccumulation, and the level in serum is an important factor to evaluate the caused health risk, which depends on efficient and sensitive analytical methods. Here, a triple signal-amplified electrochemical sensing platform based on metal-dependent DNAzymes was fabricated for sensitive determination of heavy metals in serum (copper as a model target). Under the optimized conditions, the proposed method showed good sensitivity (limit of detection, 0.33 fM for Cu2+) with excellent selectivity and stability, which is ascribed to: (i) tetrahedral DNA nanostructures (TDNs) that was used as a promising scaffold to adjust the selective transformation between heterogeneous and homogeneous reactions, preventing the nonspecific binding of electrodes surface and DNA probes; (ii) the magnetic beads (MBs) used which led to signal amplification and decreased background owing to its excellent properties of extracting equivalent targets from the complex samples; (iii) two signal amplification strategy of catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR). In addition, the proposed sensing platform displayed satisfactory accuracy through the validation with inductively coupled plasma-mass spectrometry (ICP-MS) and a spike-recovery analysis (recoveries, 87.92-111.61%; RSD, 4.89-8.85%), indicating the great potential for rapid and sensitive detection of Cu2+ or other metal ions.

Predictive model for cadmium uptake by maize and rice grains on the basis of bioconcentration factor and the diffusive gradients in thin-films technique.

It is possible for heavy metals in soils to be adsorbed by crop roots and then accumulated in crops, which eventually causes great health risk when the crops are ingested by humans. Thus, it is valuable to understand the enrichment model of heavy metals in crops. Diffusive gradients in thin-films (DGT) technique, as an in-situ passive sampling method, can be used to evaluate the bioavailable heavy metals contents in soils. In this study, data of the bioavailable cadmium (Cd) in soils determined by DGT and Cd contents uptake in rice and maize grains in Tianjin, Zhejiang and Guangxi provinces of China were collected from previous references in Web of Science. By comparing bioconcentration factors, it was found that the heavy metal concentrations accumulated in rice and maize followed a general order roots > stems or leaves > grains. An accurate and robust model for the prediction of Cd content in maize and rice grains was established based on bioconcentration factor (BCF) and the bioavailable Cd content determined by DGT method, with R2 0.986 and root mean square error (RMSE) 0.128. This result suggests that the DGT method can be good tool for predicting heavy metals uptake in crops.

A review on analysis methods, source identification, and cancer risk evaluation of atmospheric polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) have gained attention because of their environmental persistence and effects on ecosystems, animals, and human health. They are mutagenic, carcinogenic, and teratogenic. The review provides background knowledge about their sources, metabolism, temporal variations, and size distribution in atmospheric particulate matter. The review article briefly discusses the analytical methods suitable for the extraction, characterization, and quantification of nonpolar and polar PAHs, addressing the challenges. Herein, we discussed the molecular diagnostic ratios (DRs), stable carbon isotopic analysis (SCIA), and receptor models, with much emphasis on the positive matrix factorization (PMF) model, for apportioning PAH sources. Among which, DRs and PCA identified as the most widely employed method, but their accuracy for PAH source identification has received global criticism. Therefore, the review recommends compound-specific isotopic analysis (CSIA) and PMF as the best alternative methods to provide detailed qualitative and quantitative source analysis. The compound-specific isotopic signatures are not affected by environmental degradation and are considered promising for apportioning PAH sources. However, isotopic fractions of co-eluted compounds like polar PAHs and aliphatic hydrocarbons make the PAHs isotopic fractions interpretation difficult. The interference of unresolved complex mixtures is a limitation to the application of CSIA for PAH source apportionment. Hence, for CSIA to further support PAH source apportionment, fast and cost-effective purification techniques with no isotopic fractionation effects are highly desirable. The present review explains the concept of stable carbon isotopic analysis (SCIA) relevant to PAH source analysis, identifying the techniques suitable for sample extract purification. We demonstrate how the source apportioned PAHs can be applied in assessing the health risk of PAHs using the incremental lifetime cancer risk (ILCR) model, and in doing so, we identify the key factors that could undermine the accuracy of the ILCR and research gaps that need further investigation.

Multivariate correlation analysis of bio-accumulation with soil properties and potential health risks of cadmium and lead in rice seeds and cabbage in pollution zones, China.

A total of 475 representative cultivated land and 435 crop samples from 11 provinces of China were collected, and lead and cadmium in 6 polluted areas by wastewater irrigation and metallurgy industry were analyzed. Rice is the major cash crop and staple food of Chinese residents. Cabbage is also a common food in Chinese daily life. Pollution levels and spatial distribution of soil, rice, and cabbage samples were illustrated on the map. In individual or multiple areas, the multivariate correlation of heavy metal's (cadmium and lead) bio-accumulation in two kinds of plants (rice seed and cabbage) and soil properties (pH, cation exchange capacity, and organic matter) was also investigated. Spearman correlation analysis showed that soil pH values and organic matter (OM) had significant effects on the uptake of Cd and Pb in rice seed: the correlation between lg Cd BCF and pH values is -0.148* (p = 0.026), and the correlation between lg Pb BCF and pH values is -0.339** (p = 0.000). The cation exchange capacity (CEC) and pH significantly impact the Cd and Pb uptake in cabbage: the correlation between lg Cd EF and pH values is -0.199* (p = 0.040), and the correlation between lg Pb EF and pH values is -0.203** (p = 0.009). The Cd and Pb bio-concentration factor BCFs of rice and cabbage decreased with the increase of pH, CEC, and OM, except that Pb BCFs increased with the increase of OM in certain areas. The BCF of Cd varied positively from Pb in cabbage, but inversely with Pb in rice significantly at the 0.01 level (two-tailed Spearman correlation analysis). For the first time, the health quotient (HQ) of Cd and Pb in different regions was also calculated and illustrated on the map. In the soil samples of different areas, average HQ values of Cd and Pb in maturity varied from 0.0003-0.0023 to 0.0051-0.0460; average HQ values of immaturity were 0.0011-0.0103 and 0.0222-0.2014. In the rice samples of different areas, average HQ values of Cd and Pb in maturity varied from 0.305-1.360 to 0.027-0.321; average HQ values of immaturity were 0.601-2.678 and 0.053-0.633. Average HQ values orders of magnitude in the cabbage samples of different areas are the same as that of rice samples, and it is 2-4 orders higher than those in soil. Average HQ values of Cd and Pb in maturity varied from 0.152-1.354 to 0.006-0.506; average HQ values of immaturity were 0.510-4.192 and 0.022-0.207. The total HQ values ingested by children were all higher than those in adults. After investigation, it was found that the total HQ value of mature plants was also higher than that of immature plants. The results of this study would be of great help to future soil remediation with similar types.

Spatial Distribution and Bio-accumulation of Cadmium and Lead in Soil, Rice and Vegetables in Typical Pollution Areas, China.

The adverse effects of Cd and Pb on human health have been widely reported. While, there were several typical pollution areas in China which has not been investigated comprehensively and deeply. In this study, 475 soil and 472 plant samples from these pollution areas were analyzed for Cd and Pb with ICP-MS. Here, the pollution levels of different areas were analyzed and compared; the spatial distributions in soil, rice and cabbage samples were illustrated in map; and the relationships of Cd and Pb in soil and rice, soil and cabbage were also discussed. The results showed that Cd pollution still existed in some south, central-south and south-east zones except other three zones located in suburb of Tianjin, north-east and north China which might be explained by the higher background values, soil acidity, Karst landscape and metallurgy industry. Comparatively, the Pb concentrations showed lower over-standard rate. Moreover, the spatial distribution of Cd and Pb in rice and cabbage showed similar trends with those of soil samples. Particularly, the average Cd and Pb concentrations in lettuces were much higher than those in other plants. Cd and Pb concentrations in rice and cabbage showed low linear dependence with the concentrations in soil. The results in this study added basic environmental data and would be helpful to future soil remediation of these areas.

Health risk from dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in a typical high cancer incidence area in southwest China.

This study was designed to test whether the dietary intake of polycyclic aromatic hydrocarbons (PAHs) is a potential exposure source relating to the high cancer incidence area in southwest China. Duplicate plate method was used to collect food samples in rural and urban sites in the region. Questionnaire surveys were conducted among 300 local residents to obtain their dietary habits and 50 subjects were chosen to collect the samples. The 16 priority PAHs (PAH16) in composite food samples for each individual subject were measured, and non-carcinogenic and carcinogenic risks were analyzed based on the results of Monte Carlo method. The average concentration of the PAH16 in food samples was 12.04 ±â€¯8.52 ng g-1. The life time average daily benzo(a)pyrene equivalent (BaPeq) exposure dose was 6.07 × 10-6 mg kg-1 day-1. Although non-carcinogenic risk was found to be within a controllable range, the average incremental lifetime cancer risk (ILCR) was 3.7 × 10-5 for rural subjects and 6.1 × 10-5 for urban subjects, which is comparable with other regions in China. The serious risk level of 10-4 was exceeded by 10.7% of urban residents and 2.1% of rural residents. This study implies that dietary exposure to PAHs is a potential exposure source to the high cancer in the region, and further cancer risk control strategies need to be formulated.

Comparison of chemical compositions in air particulate matter during summer and winter in Beijing, China.

The development of industry in Beijing, the capital of China, particularly in last decades, has caused severe environmental pollution including particulate matter (PM), dust-haze, and photochemical smog, which has already caused considerable harm to local ecological environment. Thus, in this study, air particle samples were continuously collected in August and December, 2014. And elements (Si, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Cd, Ba, Pb and Ti) and ions ([Formula: see text], [Formula: see text], F-, Cl-, Na+, K+, Mg2+, Ca2+ and [Formula: see text]) were analyzed by inductively coupled plasma mass spectrometer and ion chromatography. According to seasonal changes, discuss the various pollution situations in order to find possible particulate matter sources and then propose appropriate control strategies to local government. The results indicated serious PM and metallic pollution in some sampling days, especially in December. Chemical Mass Balance model revealed central heating activities, road dust and vehicles contribute as main sources, account for 5.84-32.05 % differently to the summer and winter air pollution in 2014.

Spatial and Seasonal Variations of Polycyclic Aromatic Hydrocarbons (PAHs) in Ambient Particulate Matter (PM10, PM2.5) in Three Mega-Cities in China and Identification of Major Contributing Source Types.

Beijing, is the political, economic and cultural center of China. Tianjin and Shijiazhuang, located close to Beijing are also two mega-cities with huge population. The rapid economic development in the three cities in the last decades has caused severe air pollution problems, especially airborne PAHs pollution, in both gaseous and particulate phases, which has resulted in considerable harm to the health of local residents. In this study, a total of 671 air samples were collected in the three cities and reference site, and four national air quality background sites. Concentrations and seasonal variations were discussed to describe the pollution status and identify possible sources. The results showed that concentrations of BaP, a PAH that serves as an indicator of PAH pollution, exceeded the Chinese national standard by 4-12 times. PAH concentrations varied significantly in different seasons, with similar trends in the three cities. The toxic equivalents quantity (i.e., quantity of total PAHs with an equivalent toxicity to BaP) ranged from 13.35 to 22.54 ng/m(3) during the central heating period of winter and spring. These concentrations greatly exceeded the Chinese national standards for 24-h average (2.5 ng/m(3)) and annual average (1.0 ng/m(3)) concentrations of BaP. Two ratios that are indicative of PAH source, Pyr/BaP and BaP/BghiP, revealed that high percentages of the PAH pollution were contributed by coal combustion.

Polycyclic aromatic hydrocarbons and organochlorine pesticides in rice hull from a typical e-waste recycling area in southeast China: temporal trend, source, and exposure assessment.

The residue levels of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and 16 selected organochlorine pesticides (OCPs) in rice and rice hull collected from a typical e-waste recycling area in southeast China were investigated from 2005 to 2007. PAHs and OCPs also were measured in ten mollusk species (soft tissues) collected in an adjacent bay in 2007. Individual PAHs were frequently found in the entire sample set (including the rice, hull, and mollusk samples) with a detection rate of 73 %. The total concentrations of 16 PAHs (ΣPAHs) and 16 OCPs (ΣOCPs) were in the range of 40.8-432 ng/g dry weight (mean: 171 ng/g) and 2.35-925 ng/g (122 ng/g), respectively, which were comparable or higher than those reported in some polluted areas. Statistical comparisons suggested that the concentrations of contaminants in hull gradually decreased from 2005 to 2007 and the residue levels were generally in the order of mollusk, hull, and rice, on a dry weight basis. Principal component analysis in combination with diagnostic ratios implied that combustion of coal, wood, and plastic wastes that are closely associated with crude e-waste recycling activities is the main source of PAHs. The finding of decreasing trend of concentrations of PAHs in this area is consistent with the efforts of local authorities to strengthen regulations on illegal e-waste recycling activities. Composition analysis suggested that there is a recent usage or discharge of hexachlorocyclohexane and dichlorodiphenyltrichloroethane into the tested area. The estimated daily intake (EDI) of ΣPAHs and ΣOCPs (calculated from mean concentrations) through rice and mollusk consumption was 0.411 and 0.921 µg/kg body weight (bw)/day, respectively.

Investigation of radon and heavy metals in Xuanwei and Fuyuan, high lung cancer incidence areas in China.

Xuanwei and Fuyuan, two counties located in southwest China, are areas with known high lung cancer incidence. Pollution relative to coal combustion, especially serious air pollution generated by burning smoky coals in unvented households, has been thought to be the most predominant cause. Possible inorganic carcinogenic matter including radon in air and arsenic, lead, chromium, cadmium, nickel, and beryllium in water, soil, and coal were sampled and examined to find the current pollution status, distributions, characteristics, and relationships to the lung cancer incidence. The concentrations of mercury in air of Xuanwei and Fuyuan ranged from 1.7 to 205.3 ng/m3 (indoor), 1.3 to 7.5 ng/m3 (ambient). No radon concentration exceeded the World Health Organization standard. Results indicated that household stove improvement by changing stoves from unvented to vented obviously alleviated the indoor air pollution of carcinogenic metals. Most of the carcinogenic metals were also found at very low levels in water and soil, which therefore had little influence on human health. Concentrations of these elements at different sites did not vary in any relation to lung cancer incidence. The study described in this article added basic data; the results of the authors' study will be helpful in determining pollution status and to future studies on the etiology of lung cancer.

Identification of carbonates as additives in pressure-sensitive adhesive tape substrate with Fourier transform infrared spectroscopy (FTIR) and its application in three explosive cases.

Pressure-sensitive tape is often used to bind explosive devices. It can become important trace evidence in many cases. Three types of calcium carbonate (heavy, light, and active CaCO(3)), which were widely used as additives in pressure-sensitive tape substrate, were analyzed with Fourier transform infrared spectroscopy (FTIR) in this study. A Spectrum GX 2000 system with a diamond anvil cell and a deuterated triglycine sulfate detector was employed for IR observation. Background was subtracted for every measurement, and triplicate tests were performed. Differences in positions of main peaks and the corresponding functional groups were investigated. Heavy CaCO(3) could be identified from the two absorptions near 873 and 855/cm, while light CaCO(3) only has one peak near 873/cm because of the low content of aragonite. Active CaCO(3) could be identified from the absorptions in the 2800-2900/cm region because of the existence of organic compounds. Tiny but indicative changes in the 878-853/cm region were found in the spectra of CaCO(3) with different content of aragonite and calcite. CaCO(3) in pressure-sensitive tape, which cannot be differentiated by scanning electron microscope/energy dispersive X-ray spectrometer and thermal analysis, can be easily identified using FTIR. The findings were successfully applied to three specific explosive cases and would be helpful in finding the possible source of explosive devices in future cases.

Dietary exposure estimates of 16 polycyclic aromatic hydrocarbons (PAHs) in Xuanwei and Fuyuan, counties in a high lung cancer incidence area in China.

Xuanwei and Fuyuan are located in the southwest of China and have the highest lung cancer incidence in China, possibly even highest in the world. Dietary samples were collected from these two counties and the contamination status of sixteen polycyclic aromatic hydrocarbons (PAHs) were determined. PAH components, food constituents, dietary exposure level, as well as spatial difference, were studied in the different groups. The percentage of dietary intake to total intake of PAHs was calculated and the relationship between the dietary intake of PAHs and the abnormal lung cancer incidence was primarily discussed. The results showed that rice and potatoes were the main foods of the local residents in Xuanwei and Fuyuan. The daily exposure doses of Bap (benzo[a]pyrene), total PAHs, and TEQs (toxic equivalents) based on Bap toxicity in two counties were estimated to be 458 ng d(-1), 14,532 ng d(-1), and 896 ng d(-1), respectively, which were much less than those in other cities reported previously. The lower ingestion amount of food with a relatively higher content of PAHs, such as meat and fish, could account for the lower exposure doses. PAHs with less than 4 rings occupied a high percentage of the total PAHs in food samples. The exposure doses varied significantly among different sites and even different families at the same site. Dietary exposure was not the main exposure route of PAHs at most sites. It appears that there was not a direct relationship between dietary exposure and the lung cancer incidence. However, high ratios of dietary intake to total PAHs intake (1.33%-70.61%) were found in several areas and rational diet suggestions should be given in these areas in the future.

Elements in lung tissues of patients from a high lung cancer incidence area of China.

The concentrations of trace elements are closely related to tumor genesis, progression, and therapy. In order to establish the extent to which trace elements apply to lung cancer, 15 trace elements were determined in 60 lung tissue samples from residents of Xuanwei and Fuyuan, two counties with extremely high lung cancer incidences in Yunnan province, China. The results indicated that the levels of V, Fe, Zn, Cd, Ni, Cu, Se, and Pb in the lung cancer tissues were significantly different from those in benign tissues. Among the eight elements, the levels of V, Fe, Zn, and Cd in the lung cancer tissues were lower than those in the benign tissues, while those of Ni, Cu, Se, and Pb were higher. Multiple conditional logistic regression showed that among the 15 elements, Cu, Pb (ß > 0, OR > 1), and Zn (ß < 0, OR < 1) were closely related to the lung cancer. Cu and Pb were classified as risk factors for local lung cancer and Zn was identified as a protective factor. The results obtained will provide dietary suggestions in terms of how to reduce lung cancer risks by appropriately balancing the intakes of certain trace elements especially for individuals who are from those two counties.

Dietary exposure estimates of 14 trace elements in Xuanwei and Fuyuan, two high lung cancer incidence areas in China.

Xuanwei and Fuyuan, located in the Yunnan province in southwest of China, are known to have a strikingly high incidence of lung cancer. Among the many factors that have been explored, the association between lung cancer and trace elements has not received enough attention. In this study, dietary samples were collected from 60 families of the lung cancer and control groups and abundances of 14 trace elements were determined using inductively coupled-plasma mass spectroscopy. Accuracy and sensitivity of the method were demonstrated by analyzing national standard reference materials. The results showed that the dietary intake of the trace elements contributed 96.6% of total intake. Among the 14 elements tested, cadmium and titanium were found to be present at a significantly higher level in the food consumed by the cancer group than by the control group. The intake of selenium by the population living in the areas is much lower than what it should be, with the people in the cancer group experiencing even more severe selenium deficiency. In addition, in both groups, the intakes of several essential elements (iron, copper, and zinc) from food and the drinking water were found to be significantly lower than required according to the Chinese Dietary Reference Intakes. The present study of the relationship between trace element intakes of lung cancer cases and controls provides important information urgently needed for the assessment of lung cancer risk of healthy subjects. The study also gives rational dietary suggestions to local residents which is important to the early diagnosis and pretreatment of lung cancer.