Over-standard Rate Research Articles

Analysis of the effect of air purification equipment on indoor pollutants in Northeast China in winter

In this study, 3 residential buildings with installed high-efficiency filter fresh air system, coarse-efficiency filter fresh air system and air purifier were selected respectively to analyze the purification effect of different air purification equipment on indoor pollutants in winter. Data on ventilation and concentrations of PM2.5 and CO2 were collected through long-term online monitoring. The test results showed that under the same outdoor pollution condition, the average indoor PM2.5 concentration of residential buildings equipped with high-efficiency filter fresh air system and air purifier was 33.62μg/m3 and 34.32μg/m3, respectively. However, the purification effect of coarse-efficiency filter fresh air system was poor, and the indoor PM2.5 concentration over-standard rate reached 13.11%. It was a slow process for the fresh air system to reduce indoor CO2 concentration. The fresh air system needed to be opened continuously for 4 hours to stabilize the CO2 concentration, and the decrease rate could reach 53.6%. Whereas, it took only 14 minutes for natural ventilation to reduce the indoor CO2 concentration by 54.3%, but the window opening time was limited in winter. The use of high-efficiency filter fresh air system can ensure indoor comfort and maintain concentration of indoor pollutants at a low level in winter.

Pisussion on noise exposure level measurement and risk assessment of typical posts in coal-fired power plants

Objective: To study the group noise exposure level of typical coal-fired power plants and explore the establishment of risk assessment methods for noise exposed posts. Methods: In April 2020, 295 typical workers in 11 coal-fired power plants were selected as the study subjects. The noise exposure dose of typical posts and the proportion of exposure groups under different exposure doses were analyzed, and the risk assessment based on the dose-response relationship was conducted. Results: The exposure level of typical noise posts in coal-fired power plants was (84.24±4.10) dB (A) , and the over-standard rate was 44.07% (130/295) . The highest noise over-standard rate in main posts were desulfurization inspectors (51.52%) , followed by steam turbine inspectors (47.92%) and belt inspectors (46.32%) . Taking 30 years as an example, the incidence rate of occupational noise deafness of noise-exposed posts in coal-fired power plants was 12.30%. The position with the highest incidence rate was belt inspector (13.21%) , followed by steam turbine inspector (12.97%) , desulfurization inspectors (12.42%) , boiler inspectors (11.59%) and chemical water inspectors (6.89%) . Conclusion: The risk of noise exposure in coal-fired power plants is relatively high. Comprehensive control measures are recommended to effectively reduce the risk of noise deafness.

Selenium Geochemical Characteristics and Influencing Factors of Paddy Fields in Du'an County, Guangxi

This study used 21 rock samples and 193 sets of paddy soil and rice grain samples collected form Baiwang Town, an area of clastic sedimentary rocks in Guangxi, China, to evaluate the potential for selenium-rich agriculture. We analyzed the concentrations of selenium and heavy metals in the soil and rice samples, and discuss the influencing factors by means of statistics and correlation analysis. The results showed that the selenium-rich rate of paddy soil and rice grain in Baiwang Town were 67.4% and 64.8%, respectively, but the content of cadmium in the selenium-rich soil samples was generally higher than the baseline value for China and the background value for Guangxi. In comparison to the screening value of soil pollution risk for agricultural land(GB 15618-2018), the over-standard rate of cadmium was 46.1%, while the over-standard rates of other heavy metals were negligible. The comparison shows that the selenium-rich rate of rice was 61.1% in the southern area of Baiwang Town with a negligible heavy metal content, and the advantages of green selenium-rich rice planting were clear. The correlation analysis showed that secondary enrichment was the main form of selenium enrichment in the study area. The soil pH and texture of the root-zone soil also affected the selenium content of the soil. The selenium content of rice seeds was mainly affected by the selenium content, active selenium content, pH, and aluminum oxide content of the root-zone soil. The risk assessment showed that the level of dietary exposure to cadmium is generally within safe limits, but it is still necessary to strengthen the monitoring of cadmium in rice and control cadmium pollution to reduce the levels of dietary exposure, especially in the central region of Baiwang Town.

Investigation on the status of respirable dust hazards in underground mines in China

Objective: To understand the hazard degree of respirable dust (exhaled dust) in coal mine underground workplaces in China, and to provide reference for the prevention and treatment of pneumoconiosis. Methods: A total of 98 representative coal mines were selected from 2016 to 2018, and the dust concentration of the underground working face was detected by the methods of on-the-spot investigation and on-the-spot detection, the dust control measures of 29 coal mines were investigated, and the hazard degree of dust exhaling in the underground working place was analyzed statistically. Results: All 1238 samples of individual coal dust (exhaled dust) were detected in 98 underground coal mines, and the concentration was 4.0 (2.2, 7.3) mg/m(3), the over-standard rate was 73.3% (908/1238) . The concentration of coal dust (exhaled dust) in coal mining face was 5.4 (3.0, 10.6) mg/m(3), and the concentration of coal dust (exhaled dust) in heading face was 3.7 (2.1, 7.2) mg/m(3). The concentration exceeding standard rate of coal dust (exhaled dust) in coal mining face was higher than that in heading face, and the difference was statistically significant (P<0.05) . Coal seam water injection was found in 57.7% (15/26) coal mining face and 42.9% (9/21) heading face in the application of dust control measures, and the high pressure spray of shearer roadheader only accounted for 38.5% (10/26) and 28.6% (6/21) . Conclusion: The concentration of coal dust (exhaled dust) in the underground face of coal mine is seriously exceeding the standard, and the dust prevention measures have not been put in place.Compulsory standards for classified management of dust in underground coal mines should be formulated, and the research and implementation of dust control technologies should be strengthened.

Effect of hydrogeological conditions on groundwater nitrate pollution and human health risk assessment of nitrate in Jiaokou Irrigation District

Nitrate pollution in groundwater and related human health risk assessment are crucial to ensure groundwater quality safety. In this study, the grey water footprint (GWF), DRASTIC model, and human health risk assessment (HHRA) model were used to investigate the status of nitrate pollution, analyze the effect of hydrogeological conditions on groundwater nitrate pollution, and evaluate the human health risk of nitrate in the Jiaokou Irrigation District, China. The results show that the maximum and average NO3− concentrations in the Jiaokou Irrigation District were 895 and 170.73 mg/L and the over-standard rate (>20 mg/L) was over 80% (82.09%). High NO3− concentration was mainly distributed in the cultivated land. The GWF results indicate that the wastewater absorption was insufficient to bear actual pollution in this region, requiring freshwater between 0.1 × 108 m3 and 105.8 × 108 m3 to dilute the nitrate to a safe concentration. The aquifers with high vulnerability levels were observed in the central and eastern parts, which are mainly related to depth to water table (D), net recharge (R), soil media (S), impact of vadose zone (I), and hydraulic conductivity (C). High NO3− pollution in an area is generally caused by high aquifer vulnerability. Additionally, the human health risk assessment shows that the health risks for pregnant women and breastfeeding women were higher than the health risks for children in the 10–16 years age group and > 16 years of age. This research provides a basis for policy-makers to take appropriate measures for protecting groundwater from nitrate pollution.

Investigation on occupational hazards in 20 automobile manufacturing enterprises in Shandong Province

Objective: To investigate the current situation of occupational hazards in automobile manufacturing enterprises in Shandong Province. Methods: From February to May 2019, the convenience sampling method was adopted to conduct on-site occupational health surveys with 20 automobile manufacturing enterprises in Shandong Province as the survey subjects, to detect the occupational hazard factors in the workplaces and individual exposure levels, and to analyze the occupational health check results of operators. Results: There were 13 small-sized, 4 medium-sized and 3 large-sized enterprises among the 20 automobile manufacturing enterprises. The detection results of benzene and toluene in the workplaces met the occupational exposure limits, and the detection results of welding fumes, manganese and its compounds, and xylene exceed the occupational exposure limits. The maximum short-term exposure concentration (C(STE)) of welding fume in the air of workplaces was 24.23 mg/m(3), and the over-standard rate was 11.0% (16/146) . The maximum time-weighted average concentration (C(TWA)) of welding fume of operators is 10.60 mg/m(3), and the over-standard rate was 11.0% (8/73) . The maximum C(STE) of manganese and its compounds in the air of workplaces was 0.879 mg/m(3), and the of manganese and its compounds of operators was 0.175 mg/m(3), and the over-standard rate was 5.7% (4/70) . The maximum xylene C(STE) in the air of workplaces was 230.00 mg/m(3), and the over-standard rate was 3.9% (2/51) . The maximum xylene C(TWA) of operators was 70.40 mg/m(3), the over-standard rate was 3.6% (1/28) . Among the 4775 workers exposed to occupational hazards, 38 (0.80%) were suspected of electric welder's pneumoconiosis, 27 (0.57%) were suspected of manganese poisoning and 31 (0.65%) were suspected of chronic low-concentration benzene and benzene series poisoning. The detection rates of suspected occupational diseases among workers in small and medium-sized enterprises were relatively high, 2.86% (30/1048) and 4.51% (51/1132) respectively. There was a statistically significant difference in the detection rates of suspected occupational diseases among the operators of different scale automobile manufacturers (P<0.05) . Conclusion: The exposure levels of electric welding fumes, manganese and its compounds in welding jobs and xylene exposure levels in spray painting jobsin Shandong Province's automobile manufacturing enterprises are more serious. The supervision and management of occupational hygiene should be strengthened, the working environment should be improved, and the health of welding and painting workers should be protected.

Investigation of Farmland Soil and Wheat Heavy Metal Contamination Character in Jinding of Lanping

The contents of Cd and Pb in soil and wheat in Jinding of Lanping in Yunnan were investigated and sampled. And single pollution index method, comprehensive pollution index method and correlation analysis were used to evaluate heavy metal contamination in wheat and soil. Zone A is in the upper reaches of the Pijiang River, and the zone does not contain large mines, where soil in the farmland is not polluted by the heavy metals Cd and Pb. The soil in zone B is slightly polluted by Cd and Pb, and the over-standard rate of the Cd of the samples measured is 75%, and the over-standard rate of the Pb of the soil is 25%. The condition of soil polluted by two heavy metals is Cd > Pb, and the heavy metal pollution of the soil in this Zone is mainly affected by mining activities. Zone C is in the lower reaches of the Pijiang River, and the soil in Zone C is not polluted by Cd and Pb. The content of Cd and Pb in the wheat in Zone A reached the standard and was not polluted. The wheat in Zone B was not polluted by Cd and Pb. Although Cd and Pb in the soil in this Zone was over-standard, it could be concluded that Cd and Pb in the soil did not migrate to wheat. The wheat in Zone C was not contaminated by Cd and Pb.

Determination of heavy metal contents in Gardeniae Fructus and fried Gardeniae Fructus and their health risk assessment

In this study, the contents of Cu, As, Cd, Pb and Hg in 10 batches of Gardeniae Fructus and 10 batches of fried Gardeniae Fructus from Fuzhou in Jiangxi were determined by inductively coupled plasma mass spectrometry(ICP-MS), and the target hazard coefficient(THQ) for different drug users(adults and children) was calculated by using the international health risk assessment model. According to the ISO and green industry standard, the content of Hg in 4 batches of Gardeniae Fructus exceeded the standard with an over-standard rate of 40%. The THQ and total THQ of Hg in 2 batches of Gardeniae Fructus were higher than the international standard limit of Gardeniae Fructus. For 10 batches of fried Gardeniae Fructus, the content of every heavy metal and total amount of five heavy metals did not exceed the standard. However, the THQ and total THQ of Hg in 1 batch of fried Gardeniae Fructus were higher than the international standard limit of Gardeniae Fructus. As compared with Gardeniae Fructus, the contents of Cu, Pb and Hg in fried Gardeniae Fructus decreased by 34.0%, 77.6% and 23.1%; the THQ of Cu, Pb and Hg for adults decreased by 33.3%, 75.0% and 96.9%; and the THQ of Cu, Pb and Hg for children decreased by 37.5%, 75.0%, 90.7%. It showed that the contents of heavy metals in individual batches of Gardeniae Fructus in this experiment had a certain risk to human health, but the contents of these heavy metals in fried Gardeniae Fructus had no obvious effect on human health. This study provided experimental basis and research ideas for safety evaluation of Gardeniae Fructus and fried Gardeniae Fructus.

Investigation on Occupational Hazards and Control Measures in an Optical Enterprise

In this paper, the hazard factors of an optical enterprise were analyzed, and the appropriate prevention and control measures were discussed. The field investigation and detection of occupational health was applied. The on spot monitoring results showed that the over-standard rate of acetone in the workplace was 10.0%, the over-standard rate of trichloroethylene was 25.0%, the over-standard rate of dichloromethane was 50.0%, and the over-standard rate of noise was 23.8%. Acetone, trichloroethylene, dichloromethane and noise were the key points of prevention and control in this optical enterprise. It was suggested that the ventilation system of the cleaning workshop should been improved comprehensively, and the workers’ hearing protection measures should been increased to effectively protect their health.

Health risk assessment of heavy metals in agricultural soils and identification of main influencing factors in a typical industrial park in northwest China

The accumulation of heavy metals (HMs) in the soil poses a threat to human health. In this study, 62 pairs of topsoil and wheat grain samples were collected from a typical industrial park in northwest China, and the human health risks associated with cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) were assessed through multiple exposure pathways. Meanwhile, the contribution of different environmental factors and their interactions were explored by using geo-detector. Results showed that Cd concentration in the soil ranged from 0.307 to 2.491 mg kg−1, with a median value of 0.588 mg kg−1, and almost half of the samples exceeded the pollution threshold. In comparison, other elements in the soil were below their mandatory thresholds. However, it is noteworthy that in addition to the median Cd concentration in wheat grains of 0.062 mg kg−1 (0.018–0.246 mg kg−1), the Pb concentration also reached 0.2 mg kg−1 (0.1–0.7 mg kg−1), with a sample over-standard rate of 48.39%. In addition, the health risk assessment results showed that the average total hazard index (HIt) for adults and children was 1.22 and 1.53, and the total carcinogenic risk (TCRt) was 7.0 × 10−4 and 2.32 × 10−4, respectively, both above acceptable criteria. Dietary intake was the main route of exposure. Among various factors, distance from industrial enterprises, altitude, and soil pH, distance from major roads were the most influential contributors. Their interactions were more prominent than the effects of single factors and this synergy deserves attention.

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.

Simultaneous determination of aflatoxin B_1,B_2,G_1,G_2,M_1,M_2 in Eupolyphaga Steleophaga by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization

The contamination of aflatoxin B_1,B_2,G_1,G_2,M_1 and M_2 in Eupolyphaga Steleophaga was determined by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization. Chromatographic separations were carried out using a Cloversil C_(18) column( 4. 6 mm×250 mm,5 μm) that were eluted in isocratic with methanol-acetonitrile-water( 20 ∶ 20 ∶ 60) as the mobile phase. The excitation wavelength and the emission wavelength of fluorescence detector were maintained at 360 nm and 450 nm,respectively. The flow rate was 0. 8 m L·min~(-1),and the column temperature was 30 ℃ ． The sample was prepared using the immunoaffinity column,then the recovery was measured with 75. 47%-101. 8% with RSD values lower than 6. 7%. A total of 20 batches of Eupolyphaga Steleophaga samples were assayed. According to the Chinese Pharmacopoeia( 2015 edition,part 1),the aflatoxin B_1 limit should be less than 5 μg·kg~(-1),and the sum of aflatoxins( AFB_1,AFB2,AFG_1,AFG_2) should be less than 10 μg·kg-1. Therefore,the positive rate of the 20 samples was 50. 0%,and 7 batches of samples exceeded the standard,and the over-standard rate was as high as 70. 0%. Among them,aflatoxins B_1,B_2,G_1,G_2,M_1,and M_2 were detected in three batches( SD-1,AH-1,AH-3),and aflatoxins B_1,B2,G1,G2,and M1 were detected in one batch( AH-7). The results showed that the newly developed method in this work is suitable for the simultaneous determination of six aflatoxins in Eupolyphaga Steleophaga,and also suggested that it should be of high values to take the contamination with aflatoxins into concerns.

An investigation of occupational exposure to welding fume, manganese, and manganese compounds in a large container manufacturing enterprise

Objective: To investigate the current status of the occupational hazards of welding fume, manganese, and manganese compounds in the welding environment of a large container manufacturing enterprise, as well as the status of occupational health examination of workers, and to provide a basis for improving the welding environment of this enterprise. Methods: In August 2016, July 2017, and August 2018, convenience sampling was used to perform an on-site occupational hygiene survey of the welding workshop for three consecutive years, and welding fume, manganese and, manganese compounds (counted as manganese dioxide) were measured for their workplace exposure concentrations and exposure levels in workers. A comprehensive analysis was performed for the results of occupational health examination. Results: Welding fume, manganese, and manganese compounds in the welding environment gradually increased from 2016 to 2018 (χ(2)(trend)=5.14 and 5.54, P<0.05). The maximum over-standard rate of concentration-short term exposure limit was 43.3% (13/30) for welding fume and 40.0% (12/30) for manganese and its compounds, and the maximum over-standard rate of time-weighted average concentration was 26.7% (8/30) for welding fume and 23.3% (7/30) for manganese and its compounds. Abnormalities were observed in the occupational health examination of welding workers in 2016-2018, among which respiratory system abnormalities (cough, expectoration, and wheezing), nervous system abnormalities (dizziness, fatigue, sleep disorders, amnesia, hyperhidrosis, and palpitations), and electrocardiogram abnormalities (bundle conduction block) had an incidence rate of above 10.0%, and the incidence rate of abnormalities on posterior-anterior X-ray high-kV chest radiograph was close to 8.9% (30/336) . Conclusion: There is severe exposure to welding fume, manganese, and manganese compounds among workers in this enterprise, which cause great hazards to the health of workers. It is necessary to strengthen occupational health management, take measures to improve the welding environment, and enhance occupational disease prevention.

Analysis on occupational hazards monitoring and occupational health examination in a province

Objective To find out the status of the monitoring of production environment and physical condition of occupational victims in Sichuan in recent 5 years. Methods Data of health supervision of workers with toxic and harmful activity and occupational health examination in Sichuan Province during 2012-2016, monitoring of occupational harmful factors in Sichuan Province during 2014-2016 were collected from the Network direct reporting system. Descriptive analysis was conducted to analyze the result in May 2017. Results The detection rate of suspected occupational diseases in 23964 enterprises was 1.79% (13392/748291) . The exceeding standard rate of dust, noise, xenobiotic were 32.58% (5089/15622) , 20.28% (4897/24152) and 4.80% (1016/21145) respectively. In addition, state-owned enterprises, state-owned enterprises and collective enterprises showed the highest over-standard rate of dust, noise and exogenous chemical poisons, with the over-standard rate of 69.93% (828/1184) , 29.08% (608/2091) and 11.80% (42/356) respectively. The exceeding rate of dust, noise and exogenous chemical poisons was 32.76% (740/2259) , 28.72% (444/1546) and 7.39% (114/1543) , respectively. Most of the enterprises with higher over-standard rate of dust and chemical poisons are located in Suining City, Panzhihua City, Guangyuan City and Ziyang City. Conclusion The focus of occupational hazards in Sichuan is dust and noise, followed by benzene. Key words: Occupational hazards; Monitoring; Occupational health surveillance

Effect of welding operations on the health status of workers with low working age

Objective To explore the impact of welding operations on the health status of workers with low working age, and provide a basis for occupational health risk assessment for workers of low working age. Methods Used the method of cluster sampling to randomly selected workers from an automobile manufacturing plant in Guangzhou as research subjects: 982 workers with welding posts of 1 year ≤working age ≤5 years were welding groups, 707 workers with simple exposure noise of 1 year ≤working age ≤5 years were assembly groups, and 717 workers in pre-job medical examinations were pre-job groups from June 2017 to September 2018. Then conducted occupational health checks on all subjects, investigated and detected the occupational hazards in welding posts and assembly posts. Results There was no statistical difference between the noise over-standard rate of welding posts' (59.3%, 16/27) and the assembly posts' (47.4%, 9/19) (P>0.05) . The over-standard rate of welding fume, manganese and its inorganic compounds in welding posts was 11.11% (3/27) . The results of occupational health examination showed that the detection rate of disease or abnormal of the welding group was 78.4% (770/982) higher than 70.2% (496/707) in the assembly group and 53.0% (380/717) in the pre-job group (the value of 2 were 14.92 and 122.37, respectively, P<0.05) . The rate of hearing loss of the assembly group and the welding group were 14.7% (104/707) and 19.3% (190/982) , respectively, which was higher than that of the pre-job group (10.5%, 75/717) , and the hearing loss rate gradually increased with the increase of working age (the value of linear-by-linear association were 12.04 and 44.67, respectively, P<0.01) . Compared with the hearing loss rate of each working age of the assembly group, the hearing loss rate of each working age of the welding group was higher, and when the working age was 3 years, the risk of hearing loss in the welding group was 2.70 times that of the assembly group (P<0.01) . The rate of pulmonary dysfunction in the welding group was 19.2% (189/982) higher than that in the pre-job group (12.6%, 90/717) , and it increased with the increase of working age (the value of linear-by-linear association was 15.97, P<0.01) . Conclusion Welding work seriously damages the health of workers with low working age, increases the hearing loss of workers and the occurrence of pulmonary dysfunction; manganese and its compounds increases noise-induced damage to the hearing system. Key words: Welding fume; Manganese and its compounds; Low working age; Hearing loss; Pulmonary ventilation dysfunction

Pollution Characteristics and Source Apportionment of PM2.5 in Heating and Non-heating Periods in Shenyang

To study the atmospheric PM2.5 pollution characteristics and sources in heating and non-heating periods in Shenyang, 113 groups of effective PM2.5 samples were collected from January 29, 2015 to January 26, 2016, and the water-soluble ions, carbon constituents and elements in PM2.5 were tested. The results indicated that the average PM2.5 mass concentration in Shenyang during the sampling period was 66 μg·m-3. Among the sampled PM2.5 concentrations, 31.0% exceeded the daily value of the secondary standard limit of the Chinese National Ambient Air Quality Standard (75 μg·m-3). The average concentration and over-standard rate of PM2.5 in the heating period (90 μg·m-3, 68.6%) was higher than that of the non-heating period (51 μg·m-3, 31.4%). The concentrations of the 21 elements (except Mg, Ti, Ca, Fe, and Si), water-soluble ions (except Ca2+), OC, and EC were all higher in the heating period than in the non-heating period. The ratio of[NO3-]/[SO42-]showed that the influence of moving source increased obviously in the non-heating period, and fixed source was still the main contributor in the heating period. The water-soluble ions were the result of the interaction of fixed source and moving source. The NOR and SOR analyses showed that the secondary conversion of NOx was weak, and the secondary conversion of SO2 was obvious, especially in the non-heating period. The enrichment factor showed that the elements with high EF value mainly came from coal burning, traffic pollution, and industrial emissions. The reconstructed PM2.5 masses were highly correlated with the measured ones. The main constituents of PM2.5 in both heating and non-heating seasons were organic matter (28.0%, 23.1%), mineral dust (14.5%, 26.0%), and sulfate (15.1%, 19.9%), and PM2.5 was mainly affected by the secondary particles, combustion sources and dust sources.

Performance and feasibility study of hybrid ground source heat pump system assisted with cooling tower for one office building based on one Shanghai case

To relieve soil thermal accumulation and performance degradation over a long-time operation for ground source heat pump (GSHP) system in cooling-dominated area, a hybrid GSHP system with cooling tower (HGSHP) was proposed. The purpose of this paper is to study the performance and feasibility of HGSHP in Shanghai. Firstly, the simulation model of GSHP system for an office building was established by TRNSYS 17.0 and the reliability of simulation was validated by the measurement data. Then, one-year and ten-year variation of performance parameters of GSHP and HGSHP systems were calculated respectively and explored in depth. These results shown that, compared with GSHP system, the annual average electricity consumption of HGSHP system decreased by 6.40% and coefficient of performance (COP) increased by 7.12% during the first year of operation. Additionally, the outlet temperature of buried pipes was below 32 °C for HGSHP system during ten-year operation, while in GSHP system, the over-standard rate of outlet temperature of buried pipes could reach approximately 80% and soil temperature increased by 10.9 °C. These findings indicated that HGSHP system could provide a feasible solution for cooling and heating in hot summer and cold winter zones.

Determination and distribution of pesticides and antibiotics in agricultural soils from northern China.

Different types of soil samples from a typical farmland in northern China were collected and evaluated for the presence of the pesticides and antibiotics. 47 pesticides were extracted with a quick, easy, cheap, effective, rugged, and safe (QuEChERS) preparation method and cleanup with 50 mg C18, while 10 antibiotics were extracted with methanol/EDTA–McIlvaine buffer solution (v/v = 1/1), then both of them were analyzed with high performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS). Total concentrations of the 47 pesticides in the soil samples ranged from not detectable (ND) to 3.8 mg kg−1. The soil exhibited relatively high ecological risk for atrazine, chlorpyrifos, tebuconazole, difenoconazole, pymetrozine, and thiamethoxam, as over 1.0% of the sample concentrations exceeded 0.1 mg kg−1. The residual levels of the 10 antibiotics were relatively low (ND-951.0 μg kg−1). Tetracyclines exhibited a high detection rate (20.9%), with 2.8% of the soil samples exhibiting tetracyclines concentrations exceeding 100 μg kg−1, implying high ecological risk. The 4 sulfonamides and 2 macrolides analyzed showed detection rates below 0.8%. Spatial changes in the distribution of pesticides and antibiotics appear to be related to land use patterns, particularly orchards and vegetable plots. The over-standard rate of pesticides and antibiotics in orchards was greater than that of vegetable plots, and grain fields had the lowest over-standard rate. These data were helpful to figure out the pollution of these pesticides and antibiotics, and provided valuable information for soil quality assessment and risk assessment.

Rapid Determination of Carbendazim Residues in Mushrooms by Immunosorbent Assay1

In this study, the testing time was reduced to 1 h through optimizing, and an LOD of 0.3±0.15 μg·L-1 and an IC50 of 2.7±0.3 μg·L-1 were achieved by the optimized CD-ELISA. The sample extraction of 1-fold acetonitrile followed by a 20-fold dilution in assay diluted buffer has proven to be sufficient to eliminate the influence of matrix. The CD-ELISA was validated further by comparing with the standard HPLC. The average recovery ratio of 89.7%~112.7% was obtained, and the coefficients of variation were less than 11.0%. In actual samples detection, except for Pleurotus eryngii, carbendazim was not detected, and other mushrooms were all detected, and only carbendazim in Volvariella volvacea exceeded the standard, and the over-standard rate was 16.7 %. In a word, the rapid, sensitive and efficient CD-ELISA for quantifing carbendazim in mushrooms was established in the study.

Assessment of heavy metals pollution of soybean grains in North Anhui of China

Heavy metals may cause deleterious effects on human health through consumption of contaminated food crops. To assess the safety of soybean consumption, concentrations of heavy metals (Cu, Zn, Cr, Ni, Cd, As, Pb and Hg) in soybean grains sampled from the farmland in North Anhui (suitable for high-protein soybeans planting) were analyzed. The results showed that the concentrations of Ni, Cr, Cu and Pb in soybean gains exceeded the Chinese safety limits, with over-standard rate of 92.59%, 74.07%, 37.04% and 9.88% respectively. Spatial distribution of soybean pollution analysis showed that soybeans were severe polluted by Ni and concentrated in the west of North Anhui. SR-μXRF elemental maps of soybean gains indicated Cu, Cr, Ni, Pb and Hg specifically enriched at the embryo. In relation to health risks, there were no obvious non-carcinogenic risk and carcinogenic risk (CR) through ingesting soybeans from North Anhui. But it can induce a threat to people's health if the consumption of soybean exceeds the routine dose.