Search

Due to the high global warming potential and rapidly increasing atmospheric concentrations of fluorinated greenhouse gases (hereinafter referred to as F-gases), the emission estimation has been widely studied. Additionally, the atmospheric observation supports the emission estimation. However, there are few F-gas studies with respect to chemical plants. In this study, we firstly carried out atmospheric observation studies of F-gases around chemical plants in China. Four typical chemical plants were selected, and the concentration levels, their concentration differences (hereinafter referred to as the up–down difference) and enhanced ratios (hereinafter referred to as the up–down enhanced ratio) of the F-gases at upwind and downwind sites in the four plants were observed. Both the upwind and downwind observation results of each plant showed that the average concentrations of HFCs were the highest (57%–85%), followed by PFCs, while the total average concentrations of SF6 and NF3 only accounted for less than 5%. The F-gases, with both the larger up–down enhanced ratios and the larger up–down differences in each plant, may suggest larger emission strengths during fluorinated production, by-products and usage processes. Additionally, the numbers of F-gas species emitted from Plants A, B and C were all significantly higher than those from Plant D. This may be because the F-gases in Plants A, B and C were emitted not only during fluorinated production and by-product processes, but also during usage processes, with respect to refrigeration and air-conditioning or foam insulation materials. The F-gases emitted by each plant did not cause toxicity to humans at sensitive sites; however, they can cause nonnegligible climate impacts. In the future, it is necessary to select more typical chemical plants to carry out the atmospheric observation of F-gases, with a higher observation frequency and larger sample size, to further estimate F-gas emissions from chemical plants in China. [ABSTRACT FROM AUTHOR]

1,1,1,2-tetrafluoroethane (HFC-134a) is a potent greenhouse gas that can be degraded to produce trifluoroacetic acid (TFA), a degradation product that has an impact on aquatic ecology, so its emission has been a continuous concern worldwide. Existing studies mainly estimate the global- or national-scale emissions of HFC-134a, and there are relatively few studies on regional emissions, all of which used the top-down method. By establishing a regional-scale bottom-up emission inventory and comparing it with the regional-scale top-down estimation results, regional emissions can be verified and their emission characteristics and environmental impacts can be analysed. HFC-134 emissions were estimated for the first time in the North China Plain using the emission factor method, and spatiotemporal characteristics and environmental impacts were analysed for the period of 1995 to 2020. The results showed that the cumulative HFC-134a emissions were 88 (73–103) kt (126 Mt CO2-eq), which have led to an increase in global radiative forcing of 1.1 × 10−3 (0.9 × 10−3–1.3 × 10−3) W m−2, an increase in global surface temperature of 8.9 × 10−4 °C, and a cumulative TFA production of 7.5 (6.2–8.9) kt as of 2020. The major sources of HFC-134a emissions are the refrigeration and air conditioning sector, which involves the automotive air conditioning (MAC), industrial and commercial refrigeration, and air conditioning (ICR) sub-sectors. China joined the Kigali Amendment in 2021 to phase down HFCs and proposed the goal of carbon neutrality by 2060. The North China Plain is a region undergoing rapid economic development, with a relatively high proportion of GDP (29%) and car ownership (23%) in 2020. Additionally, HFC-134a emissions accounted for about 20% of the total emissions in China. Therefore, HFC-134a emissions and their environmental impact on the North China Plain should not be ignored. [ABSTRACT FROM AUTHOR]

The eutrophication of water in reservoirs and lakes is worsening year after year and has become a prominent issue of environmental water protection. In order to understand the degree of eutrophication and the changing trend of important drinking water sources in the coastal areas of Western Guangdong, ensuring the safety of drinking water, this paper takes Gaozhou Reservoir as the research object. According to the long‐term monitoring results of eutrophication index of reservoirs from 2012 to 2019, spatial and temporal analysis of each evaluation indicator and the comprehensive nutrient status of the reservoir was conducted using the integrated nutrient status index method. Based on the Weber–Fechner (W‐F) law, an early warning model for reservoir eutrophication and grading evaluation was established. The results showed that Gaozhou Reservoir was in mesotrophic state, and the eutrophication was more serious in the high water period than in the low water period. TLI (TN) was the largest contributor to eutrophication of the reservoir, and all nutritional status indexes show mild eutrophication. Chl‐a, phosphorus nutrients and organic matter had little effect on the degree of eutrophication. The fluctuation of the eutrophication status at each monitoring section of the reservoir was relatively stable. The TLI(Σ) of Liangde Dam was lower than that of the Shigu Reservoir, and the comprehensive nutritional status of the Shigu area in the decreasing order was tail > supply port > centre. According to the established early warning model, the eutrophication status in different seasons from 2012 to 2019 was evaluated. The results indicated that the comprehensive influence index value of the dry period was less than that of the flood period due to the influence of seasonal factors. In addition, the model has a good warning effect; it provides theoretical support and prevention and control methods for ecological environmental protection of reservoirs. [ABSTRACT FROM AUTHOR]

Complex adaptation systems are the main development direction of China's current green innovation research. New material industry is one of the key entry points to accelerate the construction of modern industrial system and promote innovation, green, and efficient development. Under the requirements of China's current low-carbon development, China's green innovation system is developing rapidly. Green innovation complicates traditional innovation models and their functions and improves economic development. The purpose of this paper is to study the theoretical analysis framework of applying complex adaptive systems and to analyze and calculate the characteristics of the current status of green innovation systems in multiple industries in China's manufacturing industry. Analysis is as follows. The experimental group and the control group are set for comparison, and the data are organized by applying complex adaptive system theory and data analysis methods. Experimental data show that the coordinated development of the green innovation systems in various industries in China is not balanced, with a difference of more than three times; the parameters of the various green innovation systems within the industry are unbalanced, and the difference is more than five times. The experimental results show that the green innovation subject can strategically interact by adjusting the ratio of resource allocation through the constructed green innovation system model. The green innovation system with complex adaptive system theory is conducive to the development of the green system. It can save about 23% of green innovation time and improve efficiency by about 15%, to promote the development of green innovation in China. [ABSTRACT FROM AUTHOR]

Electrochemiluminescence biosensor is an analytical method combining electrochemiluminescence technology with biosensor. Using nanomaterials as electrochemical luminescence sensor platform can not only immobilize a large number of biomolecules but also improve the performance of the sensor to realize the supersensitive detection of biomacromolecules. Although these methods have high sensitivity for bioanalysis, there are still some shortcomings which limit the practical application. Therefore, this paper discusses the development of functional gold nanomaterials industry and its application in chemiluminescence bioanalysis. In this paper, two methods of synthesizing luminescent functional gold nanomaterials at room temperature were studied by using chemiluminescent reagents as reducing agent and protective agent. Based on luminescent functionalized gold nanoparticles, immunoassay and DNA bioanalysis probes were constructed, and their applications in chemiluminescence and electrochemiluminescence bioanalysis were discussed. Finally, the simulation results show that the relative deviation between the experimental results and the existing clinical methods is less than 17%. The sensor has good stability and selectivity and can be used for the determination of CEA in human serum. The gold nanomaterials synthesized by further research have excellent chemiluminescence activity and can be used to label biomolecules and prepare biological probes. This article aims to explore the application of chemical methods in the transformation of new industries, to achieve breakthroughs in new products in industrial innovation, and to achieve the cross-fusion of management science and engineering disciplines and chemical disciplines. The industrial development of derivative functionalized gold nanomaterials has broad application prospects in biological analysis. [ABSTRACT FROM AUTHOR]

The GIS-based water quantity and water quality model is widely used to provide decision-making supports for water resource and water quality management. However, the existing integration patterns of GIS and model system mainly depend on data communication between themselves which may lead to low operating efficiency and time-consuming model setup. In this paper, a generalized data structure (dual object structure (DOS)) which can store the data of GIS objects and model objects together is proposed and realized for the first time, avoiding frequent data communication during the period of numerical simulation and result expression, realizing the fusion of GIS objects and model objects at the data structure level, improving the operating efficiency of the system. Finally, the water quantity and water quality modeling software (digital basin simulation system (DBSS)) based on DOS was developed by using C++ language. The software has been applied successfully in large-scale river basins of China, and one of the cases was demonstrated to show the application process and the outstanding results. [ABSTRACT FROM AUTHOR]

Objective: To investigate a novel gene mutation in a Chinese patient with non‐syndromic hypodontia. Subjects and Methods: Mutation analysis was carried out by whole exome sequencing. Bioinformatics tools were used for the biophysical predictions of the mutative protein. Luciferase reporter assay was performed to analyse the effects of mutation on protein function. PAX9 and BMP4 gene expression from mutant cells was detected by qRT‐PCR. Results: A novel heterozygous mutation (c.G1057A) was detected in the patient but was not found in the controls. The novel missense mutation led to a Val111Met substitution in the paired box domain which was completely conserved evolutionarily, as analysed by dbNSFP. The mutation was predicted to be disease‐causing and harmful using MutationTaster and CADD, respectively. Protean of Lasergene showed that this mutation may lead to β‐region shortening in the mutant protein compared to the wild type. Luciferase reporter assay indicated that the mutated protein reduced the transactivation activity of PAX9. This mutation led to increased levels of PAX9 transcript and reduced levels of BMP4 transcript, likely due to compensatory activation and lower transactivation activity of mutant PAX9. Conclusion: This novel mutation (c.G1057A) in PAX9 caused hypodontia by altering PAX9 gene function and downregulating BMP4 gene expression. [ABSTRACT FROM AUTHOR]

The wide dissemination of New Delhi metallo-β-lactamase genes (blaNDM) has resulted in the treatment failure of most available β-lactam antibiotics, with IncX3-type blaNDM-5-carrying plasmids recognised as having spread worldwide. In China, bacteria carrying these plasmids are increasingly being detected from diverse samples, including hospitals, communities, livestock and poultry, and the environment, suggesting that IncX3 plasmids are becoming a vital vehicle for blaNDM dissemination. To elucidate the fitness cost of these plasmids on the bacterial host, we collected blaNDM-negative strains from different sources and tested their ability to acquire the blaNDM-5-harboring p3R-IncX3 plasmid. We then measured changes in antimicrobial susceptibility, growth kinetics, and biofilm formation following plasmid acquisition. Overall, 70.7% (29/41) of our Enterobacteriaceae recipients successfully acquired the blaNDM-5-harboring p3R-IncX3 plasmid. Contrary to previous plasmid burden theory, 75.9% (22/29) of the transconjugates showed little fitness cost as a result of plasmid acquisition, with 6.9% (2/29) of strains exhibiting enhanced growth compared with their respective wild-type strains. Following plasmid acquisition, all transconjugates demonstrated resistance to most β-lactams, while several strains showed enhanced biofilm formation, further complicating treatment and prevention measures. Moreover, the highly virulent Escherichia coli sequence type 131 strain that already harbored mcr-1 also demonstrated the ability to acquire the blaNDM-5-carrying p3R-IncX3 plasmid, resulting in further limited therapeutic options. This low fitness cost may partly explain the rapid global dissemination of blaNDM-5-harboring IncX3 plasmids. Our study highlights the growing threat of IncX3 plasmids in spreading blaNDM-5. [ABSTRACT FROM AUTHOR]

• We addressed soil carbon fluxes in saline-alkaline grasslands. • Light grazing showed a negative effect on SR h. • Seasonal fluctuation of grazing effects resulted in unaltered seasonal mean SR. • Annual precipitation regulated the interannual variation of soil C emissions. • Soil environment explained SR more than plants and soil microorganisms. Grazing is a prevalent management strategy in grassland ecosystems that has profound effects on plants and soil microorganisms, consequently altering soil carbon (C) fluxes. However, the difference responses and regulatory mechanisms of soil autotrophic respiration (SR a) and heterotrophic respiration (SR h) to different grazing intensities remain unclear, especially in saline-alkaline grasslands. A six–year (2017–2022) field experiment involving four grazing intensities (no grazing, light grazing, moderate grazing, and heavy grazing) was conducted in a saline-alkaline grassland located in the agro-pastoral ecotone of northern China. Soil total respiration (SR tot) and its components (SR a and SR h), and the related biotic and abiotic factors (plants, soil microorganisms, and soil environment) were measured. The results showed that light grazing significantly decreased the mean SR h by 17.7% across six measuring years. The effects size of grazing on soil respiration fluctuated consistently with soil water content during the growing seasons (May–September), resulting in a neutral effect of grazing on the seasonal mean SR a. The cumulative soil C emissions of the current year varied with the seasonal precipitation in the previous year, whereas the changes in cumulative soil C emissions induced by grazing showed the same trends as annual precipitation. In addition, the key control factors for SR h and SR a differed and varied with grazing intensity and the soil environment played a critical role in regulating soil C fluxes. In conclusion, light grazing reduces soil microbial-driven C emissions and the soil environment and precipitation co-regulate the response of soil C fluxes to different grazing intensities in saline-alkaline grasslands. [ABSTRACT FROM AUTHOR]

Long-term heavy metals accumulation caused by acid mine drainage (AMD) irrigation in paddy soils poses a severe threat to environmental health. However, the soil adsorption mechanisms under AMD flooding remain unclear. This study provides key insights into the fate of heavy metals in soil, particularly the retention and mobility mechanisms of Cu (copper) and Cd (cadmium) after AMD flooding. The migration and fate of Cu and Cd in uncontaminated paddy soils treated by AMD in Dabaoshan Mining area was investigated via column leaching experiments in the laboratory. The maximum adsorption capacities of Cu (658.04 mg kg -1 ) and Cd (335.20 mg kg -1 ) cations were predicted and the breakthrough curves were fitted using the Thomas and Yoon-Nelson models. Our findings demonstrated that Cd was more mobile than Cu. Furthermore, the soil had a greater adsorption capacity for Cu than Cd. Tessier's five-step extraction method was used to determine Cu and Cd fractions in leached soils at different depths and times. After AMD leaching, the relative and absolute concentrations of the easily mobile forms were all increased at different soil depths, thus increasing the potential risk to the groundwater system. Mineralogical characterization of the soil indicated that AMD flooding leads to the formation of mackinawite. This study provides insights into the distribution and transportation processes of soil Cu and Cd and their ecological effects under AMD flooding, as well as a theoretical basis for the establishment of corresponding geochemical evolution models and environmental governance in mining areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Environmental release of acid mine drainage (AMD) poses a potential threat to the environment and human health due to its high content of heavy metals. The impact of AMD flooding on unpolluted soil leads to serious pollution over time via a complex process, related to the geochemical behavior of toxic metals that so far has only been partially investigated. Here, a soil column study was conducted to investigate the migration of Cu and Cd fractions in unpolluted paddy soil following treatment with AMD collected from the Dabaoshan Mining area. Tessier's sequential extraction was performed to fractionate the metals at various depths over time. After 160 days of experimental flooding, the soil pH stabilized at 2.52 at a column depth of 5 cm. The fractions of Cu and Cd that were highly mobile increased significantly during AMD flooding. For Cd, the latter already occurred on day 67. At a depth of 20 cm, the total content of Cu maximally increased from initially 26.89 mg kg -1 to 696.96 mg kg -1 on day 160, while the content of Cd maximally increased from 0.22 mg kg -1 to 391.30 mg kg -1 on day 67. Reduced partition index analysis conformed that the mobility of both Cu and Cd significantly increased in contaminated soil during continuous AMD flooding. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) identified a changed distribution of the elements in the soil, with Fe appearing to have aggregated. The correlation analysis between Cu and Cd in pore water and in different fractions in the soil's solid phase identified a dynamic distribution of these metals in certain geochemical components during their migration. The results of this study contribute to a scientific foundation to describe the geochemical behavior of heavy metals in soil subject to AMD flooding., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The environmental problems caused by mining are continuous and multifaceted, in order to help manage and plan restored mining areas, the bioavailability of metals is an effective tool for measuring the potential risks to human health. This study analyzes the geochemical fractions of eight metals (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) to compare their bioavailability and establishes a Hierarchical health risk (HHR) model to assess the human health risks of the mine area after restoration. The results indicated that children have the highest non-carcinogenic risks exposed through ingestion (HI-ingestion) due to their special behaviors; HI-dermal may be enriched in the body; and HI-inhalation is lowest, as it is related to soil particle size. Affected by local economic development, environmental climate, soil type, and mining, the carcinogenic risk of exposure through the skin (CR-dermal) for adults significantly exceeds the acceptable safety level (ASL). The spatial distribution shows that the harm of mining to human health is a continuous process. There was still a significant CR for adults after remediation, and the HI of tailings exposure was more serious. The Classification and Regression Tree (CART) model of metal bioavailability was developed by integrating the extrinsic and intrinsic factors of metals to explore the effects of different factors on metal bioavailability and predict. The results showed that the bioavailability of metals was a dynamic process that combined land use, the distance to traffic roads, physicochemical properties of soil, and geochemical fractions of metal, and that it affects human health both directly and indirectly. Due to the fragility and sensitivity of the ecosystem after the mining area is restored, it may face greater environmental health risks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Although the mining area has been restored, the environmental problems caused by years of large-scale oil shale mining are still continuing, coupled with the intensive distribution of the surrounding petrochemical industry, posing a serious threat to the local ecological environment. In this study, we investigated eight heavy metals (Cu, Ni, Pb, Cd, As, Cr, Mn and Zn) contamination and distribution around mining area, evaluated the potential risks of environment, identified the main sources of metal pollution and performed source apportionment. The results showed that the original north and south dumps were seriously polluted, and the CF values were significantly higher than other sampling sites. Ni, Zn and Mn have high coefficients of variation, which may be greatly affected by human factors and especially the waste slag piled up. The concentration of heavy metals in the water was lower than in the soil; soil particles, pH, Eh and acid mine drainage influence the variation of heavy metal concentrations. As and Cd have very high RAC values, and accordingly they were mainly present in the exchangeable and reduced fractions. Mn was exposed to higher ecological risks, followed by Pb, although there were high loads on carbonate bound and oxidizable fractions. APCS-MLL receptor model was used to identify and apportionment three main sources of contamination. The mean contribution rates of industrial activity, atmospheric deposition and mixed sources accounted for 39.77%, 22.24% and 37.99%, respectively. Cluster analysis further classified the metal pollution sources according to the spatial distance of sampling points., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Two Gram-negative, aerobic, motile bacteria strains were isolated from leaf spot disease of Quercus mongolica . Strain hsmgli-8 T has 99.86 % 16S rRNA gene sequence similarity to LY10J, and the highest 16S rRNA gene sequence similarity to Pseudomonas cerasi 58 T (97.2 %), then Pseudomonas ficuserectae JCM 2400 T (97.18 %), Pseudomonas meliae CFBP 3225 T , Pseudomonas tremae CFBP 6111 T and Pseudomonas congelans DSM 14939 T (all 97.12 %), and less than 97.1 % similarity to other recognized species. In phylogenetic trees based on 16S rRNA gene and multilocus sequence data, the two novel strains form a separate branch, indicating that they do not belong to any Pseudomonas group and subgroup, and should belong to a novel species within the genus Pseudomonas . This assertion is also supported by the results of genome average nucleotide identity analysis. The major fatty acids are C 16 : 0 , C 18 : 1  ω 7 c and/or C 18 : 1  ω 6 c , C 16 : 1  ω 7 c and/or C 16 : 1  ω 6 c . Polar lipids include phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, aminolipid and seven uncharacterized phospholipids. The predominant respiratory quinone is Q-9. The DNA G+C content is 59.45-59.50 mol%. Based on these data, we propose that the two novel strains should be assigned as a novel species within the genus Pseudomonas . We propose that the novel strains be named Pseudomonas quercus sp. nov. The type strain is hsmgli-8 T (=CFCC 15739 T =LMG 31544 T ).

The aim of the present study was to reveal the physical symptom changes and their correlations with mental health status in deep underground miners.A total of 286 deep underground miners completed a cross-sectional questionnaire study at China Pingmei Shenma mine complex. The questionnaire included sociodemographics, self-reported physical symptoms, underground adverse environmental factors, and the Symptom Checklist-90-Revised (SCL-90-R). Five environmental parameters of 1 deep mine were also measured.Data from 266 valid questionnaires were analyzed. The 3 most frequent complaints about underground adverse conditions were moisture [62.03% (165/266)], dim light [45.86% (122/266)], and high temperature [42.11% (112/266)]. Fatigue [40.22% (107/266)], hearing loss [34.96% (93/266)], and tinnitus [31.58% (84/266)] were reported to be the three most common physical symptoms. Insomnia was reported in 204 participants (76.69%) mainly due to the difficulty of falling asleep [42.35% (84/204)] and dreams [39.70% (81/204)]. Mean scores of SCL-90-R subscales including somatization, anxiety, phobic anxiety, psychoticism, and paranoid ideation were elevated compared to Chinese norms, while there was diminished interpersonal sensitivity. Univariate analyses indicated that the 3 most common physical symptoms were associated with poorer SCL-90-R scores. With increasing depth below ground, air pressure, relative humidity, CO2 concentration and temperature rose, while total gamma radiation dose-rate decreased.The physical and mental health status of deep underground miners was poorer than the general Chinese male population. Some adverse environmental factors were identified that may have influenced health status. Measures are suggested to improve the deep underground working environment.

This study reports the subjective perceptions and mental state of employees working in the Erdaogou Mine, affiliated with Jiapigou Minerals Limited Corporation of China National Gold Group Corporation (CJEM); these employees are pioneers working at the deepest point below ground in China. The data represent a valuable baseline from which to assess the effects of the environmental factors in the deep-underground on human physiology, psychology, and pathology.The air pressure, relative humidity, temperature, total γ radiation dose-rate, and oxygen concentration in the CJEM in the aisles in goafs at 4 depths below ground were measured. Study subjects were administered a study-specific questionnaire that included items that targeted factors with potential to affect respondents' health and wellbeing and included the symptom checklist-90-revised (SCL-90-R).Air pressure, relative humidity, and temperature rose, total γ radiation dose-rate decreased, and there was no change in oxygen concentration with increasing depth below ground. Most (97.2%) respondents had a negative impression of the ambient conditions in the deep-underground space. The most commonly perceived adverse factors included moisture (74.9%), heat (33.5%), and poor ventilation (32.4%). 93.29% of respondents associated ≥1 self-reported negative physical symptom with working in the deep-underground space; the most frequent symptoms were being easily tired (48.7%), tinnitus (47.5%), and hearing loss (44.1%). Higher SCL-90-R scores were associated with the perception of >1 adverse factor in the deep-underground, spending >8 hours continuously in the deep-underground space, or working at a depth > 1000 m below ground. >1 perceived adverse factor in the deep-underground and continuously spending >8 hours in the deep-underground space were significant predictors of high SCL-90-R scores.Adverse factors, including high temperature, humidity, and dim light, may have negative impacts on the physical and psychological health of people who spend long periods of time living and/or working in the deep-underground space.

The world is entering a new era of exploring and exploiting the deep-underground space. With humans poised to reach historical depths in the use of the deep Earth, it is essential to understand the effect of the deep-underground environment on the health of humans and other living organisms. This article outlines the history and development of biological research conducted in deep-underground laboratories and provides insight into future areas of investigation. Many deep-underground laboratories have investigated the effects of reduced cosmic ray muons flux, searching for rare events such as proton decay, dark matter particles, or neutrino interactions, but few have focused on the influence of the environmental factors in the deep-underground on living organisms. Some studies revealed that prokaryote and eukaryote cells maintained in low levels of background radiation exhibited an stress response, which manifested as changes in cell growth, enzyme activity, and sensitivity to factors that cause genetic damage; however, the underlying mechanisms are unclear. There remains an urgent need to understand the detrimental and beneficial biological effects of low background radiation and other factors in the deep-underground on humans and other organisms. Consequently, a multidisciplinary approach to medical research in the deep-underground has been proposed, creating a new discipline, deep-underground medicine, and representing a historical milestone for exploring the deep Earth and in medical research., (Copyright © 2018. Published by Elsevier Ltd.)

Previous studies concerning the association between nonoccupational physical activity (PA) and risk of ovarian cancer yielded mixed results. We investigated the association by performing a meta-analysis. Relevant studies were identified by searching PubMed and EMBASE to June 2014. We calculated the summary relative risks (RRs) and 95% confidence intervals (CIs) using random-effects models. The dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression. Nine cohort studies and ten case-control studies involving 730,703 participants and 9,459 cases of ovarian cancer were selected for meta-analysis. The analyses showed that individuals who participated in any amount of nonoccupational PA had a RR of 0.92 (95% CI = 0.84-1.00) for risk of ovarian cancer. Those who participated in high or moderate nonoccupational PA had a RR of ovarian cancer risk of 0.89 (95% CI = 0.79-1.01) and 0.91 (95% CI = 0.85-0.99), respectively. Stratifying by study design and cancer subtype (borderline and invasive tumors), inverse association was only found in case-control studies. A linear but not significant dose-response relationship was found between nonoccupational PA and ovarian cancer risk. In conclusion, a weak inverse association exists between nonoccupational PA and the risk of ovarian cancer. Regarding the significant heterogeneity among included studies, confirmation in further prospective cohort studies with more accurate assessment of PA level is essential.