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1.
A trend in consolidating livestock and poultry operations into concentrated animal feeding operations (CAFOs) potentially increases farm worker exposure to the hazards associated with high animal density conditions. The two main contributors of documented injury (fatal and non-fatal) are related to accidents with machinery and animals. Tractor rollovers are the leading accident in the area of farming machinery issues; kicks, bites, and workers being pinned between animals and fixed objects are non-machinery issues typically caused by inadequate precautions taken in the vicinity of livestock. These types of accidents are well documented; however, recommended safety strategies continue to be studied to reduce the risks and numbers of injuries associated with both machines and animals. Unlike accidents involving machinery and animals, air emission exposure and potential health effects from CAFOs are not well documented. CAFOs have the potential to show higher gaseous and particulate matter emissions compared to smaller farms. Pollutants like hydrogen sulfide, ammonia, volatile organic compounds, particulate matter, and endotoxin are emitted on CAFOs and can potentially affect worker health. These specific air emissions, their sources, and some of their harmful capabilities have been identified, and regulations have been implemented to create improved work environments on CAFOs. Despite such precautions, farm workers continue to report respiratory health symptoms related to their work environment. Air pollutant exposure and its health effects on farm workers require focused research to arrive at improved safety strategies that include mitigation techniques and protective gear to minimize adverse effects of working in CAFOs.  相似文献   

2.
Ceftiofur is a third-generation cephalosporin antibiotic that has been widely used to treat bacterial infections in concentrated animal feeding operations (CAFOs). Land application of CAFO waste may lead to the loading of ceftiofur residues and its metabolites to the environment. To understand the potential contamination of the antibiotic in the environment, the degradation kinetics and mechanisms of ceftiofur in solutions blended with and without the recycled water derived from a beef farm were investigated. The transformation of ceftiofur in aqueous solutions in the presence of the CAFO recycled water was the combined process of hydrolysis and biodegradation. The total degradation rates of ceftiofur at 15 °C, 25 °C, 35 °C, and 45 °C varied from 0.4-2.8×10(-3), 1.4-4.4×10(-3), 6.3-11×10(-3), and 11-17×10(-3) h(-1), respectively, in aqueous solutions blended with 1 to 5% CAFO recycled water. Hydrolysis of ceftiofur increased with incubation temperature from 15 to 45 °C. The biodegradation rates of ceftiofur were also temperature-dependent and increased with the application amounts of the recycled CAFO water. Cef-aldehyde and desfuroylceftiofur (DFC) were identified as the main biodegradation and hydrolysis products, respectively. This result suggests that the primary biodegradation mechanism of ceftiofur was the cleavage of the β-lactam ring, while hydrolytic cleavage occurred at the thioester bond. Unlike DFC and ceftiofur, cef-aldehyde does not contain a β-lactam ring and has less antimicrobial activity, indicating that the biodegradation of ceftiofur in animal wastewater may mitigate the potentially adverse impact of the antibiotic to the environment.  相似文献   

3.
We examined water quality indicators (pH, temperature, turbidity, total phosphorus, and fecal coliform density) and bacterial antibiotic resistance (prevalence, conjugative transfer, and genetic linkage of resistance elements) at locations impacted by confined animal feeding operations (CAFOs) and compared them to nearby reference sites. Sites located upstream and downstream of two wastewater treatment facilities were also compared. Sites near CAFO farms had poor water quality (elevated total phosphorus and turbidity), while water quality remained relatively good downstream of wastewater treatment plants. High proportions of antibiotic-resistant bacteria were observed at all study sites, and frequent conjugative transfer of resistance was observed in laboratory assays. Out of a total of 830 environmental bacterial isolates, 77.1% were resistant to only ampicillin, while 21.2% were resistant to combinations of antibiotics including ampicillin (A), kanamycin (K), chlorotetracycline (C), oxytetracycline (O), and streptomycin (S). Multi-drug-resistant bacteria were significantly more common at sites impacted by CAFO farms. In conjugation assays, 83.3% of the environmental isolates transferred one or more antibiotic resistance genes to a laboratory strain of Salmonella typhimurium. A subset of multi-drug-resistant (A, C, and O) isolates was screened for specific tetracycline resistance genes and class I and II integrons. None of the screened isolates (n?=?22) were positive for integrons, while 13 isolates contained resistance genes for tet (B) and tet (C). Our results indicate that CAFO farms not only impair traditional measures of water quality but may also increase the prevalence of multi-drug-resistant bacteria in natural waters.  相似文献   

4.
挥发性有机化合物（volatile organic compounds, VOCs）是大气污染物的重要组成成分，对环境和人体健康有潜在危害。生猪养殖业是畜牧业的支柱产业，但其发展受到猪场排放的VOCs等引起的空气污染严重制约。该研究从特征和减排技术两个方面对猪场的VOCs进行综述，重点介绍了猪场VOCs的来源、种类及其特征、致臭性VOCs的特征和检测方法等，从源头减排、过程控制与末端处理 3 个环节对猪场VOCs减排技术进行分析和探讨，并对该研究领域的发展趋势与研究重点进行展望，以期为开展畜牧业VOCs污染减排技术研究和推动畜牧业可持续发展提供参考。  相似文献   

5.
Abstract. The intensity of animal production around the world has increased substantially during the last half-century, which has led to large problems with the disposal of manures and waste waters. The focus of this paper is on the development of national policies to improve the nutrient management of concentrated animal feeding operations (CAFOs), where nutrients are invariably in surplus. To create proper nutrient management strategies for CAFOs, and to avoid environmental problems when surplus nutrients enter air, soil and water, we need to know the number of animals/birds in the unit, the quantity of manure/slurry produced, how this material is stored and handled and how much land is available for manure spreading. In this paper, we discuss the development of nutrient management strategies for CAFOs in Europe and North America, and the voluntary measures and environmental regulations related to this. For the planning of nutrient management to be comprehensive and efficient, we need expertise from several disciplines. This planning includes development of: animal diets that reduce the amounts of excreted nutrients; efficient storage and land application technologies; land application programmes to optimize yields and reduce nutrient losses; and strategies for use of excess manure outside the farm. Also, large-scale efforts involving many stakeholders (farmers, governments and private industry) are needed to solve problems with nutrient imbalances over the long term. Efforts along these lines include manure relocation, alternative uses of manures, nutrient trading, and a general extensification of animal agriculture. The overall guiding principle for policies and planning should be a balance of nutrients, on farms as well as at larger scales.  相似文献   

6.
规模化养猪场典型沼气工程各排放节点氨排放特征研究   总被引：1，自引：2，他引：1  
为了解典型规模化猪场沼气工程的氨排放特性,选取长三角地区某规模化养猪场的典型沼气工程为研究对象,在沼气工程设施的不同氨排放暴露节点(集粪池、调节池和沼液池)设置监测点对氨排放进行连续3d的同步监测,测定处理设施各排放节点氨浓度,核算各排放节点粪便氨排放速率,分析各排放节点氨排放特征。研究结果表明,集粪池、调节池和沼液池的氨日均排放速率分别为1.48、3.08和1.47 g/(d·m2);各节点氨排放具有明显的日变化过程,大致表现为早晨氨排放呈波动增大趋势,午后开始降低,至夜间保持低值排放;集粪池、调节池在粪污周转时段出现日排放峰值;沼液池、集粪池和调节池静置阶段氨小时排放速率与温度呈正相关,与湿度呈负相关;集粪池、调节池和沼液池日氨排放量分别为13.44、38.72和5 275.4 g/d。  相似文献   

7.
Most ammonia (NH3) emissions (85%) in Canada come from agricultural sources (400 kt/yr). There are international conventions that require countries to mitigate NH3 emissions but there are no federal or provincial guidelines in Canada stipulating emission targets or best practices for agriculture. This study examines the potential for mitigating atmospheric NH3 using a range of approaches. Taking current farm practices into account, employing proven low‐cost measures (low‐emission slurry application and slurry storage covers) would reduce annual emissions from livestock operations by 16 kt NH3‐N, while using all available low‐cost measures would reduce emissions by 79 kt NH3‐N or 26% of livestock emissions. Another 36 kt/yr could be avoided by improving fertilizer practices, so that the total potential reduction would be about 29% of all agricultural emissions. Emissions from beef cattle and pig production could be reduced by 18% if consumption was cut by 50%, with greater mitigation if production for export was reduced, although the economic and social consequences need to be considered. Mitigation practices must be viewed in the context of possible pollution swapping especially in surplus nitrogen situations. Emissions must also be considered in terms of atmospheric NH3 transport to and from the USA, therefore bi‐national agreements to jointly reduce emissions might be needed. It may be more cost‐effective in Canada to strategically reduce emissions to minimize risks to health (from particulate matter) and the environment rather than to reduce annual national emission targets.  相似文献   

8.
北京地区畜禽温室气体排放的时空变化分析   总被引：5，自引：0，他引：5  
运用IPCC估算农业温室气体排放指南, 对1978-2009年期间畜禽存栏统计数据进行分析, 研究北京地区畜禽养殖温室气体排放的时空分布。结果表明, 北京地区畜禽温室气体排放自20世纪90年代初逐步增长, 到2004年达到顶峰, 之后有所回落。在3类排放的温室气体中, 牲畜肠道发酵产生的甲烷比重最大, 年平均排放量为0.4 Tg CO2-eq, 排放贡献最大的是牛, 占肠道发酵甲烷排放总量的54%; 牲畜粪便排放的甲烷平均值为0.2 Tg CO2-eq, 牲畜粪便排放的氧化亚氮平均值为0.3 Tg CO2-eq, 畜禽粪便管理排放的甲烷和氧化亚氮主要来自猪的排放, 其贡献率分别为73%和46%。从1978-2009年北京畜禽温室气体排放CR4指数(产业集中度指数)逐步增高可以看出, 北京市畜禽产业集约化水平不断提高, 其中顺义、大兴、密云和通州是北京畜禽温室气体排放的主要区域。同时, 对历年畜禽温室气体排放进行了线形回归预测, 结果显示, 北京地区的畜禽温室气体排放仍呈递增走势。结合北京地区畜禽产业温室气体排放的特点与存在问题, 笔者认为应尽快提出适合畜牧业可持续发展的温室气体减排策略及减排目标, 开展温室气体减排技术研发, 从而推进畜禽产业的可持续发展。  相似文献   

9.
There have been very few epidemiological studies dealing with pig farmers' musculoskeletal health. The aim of this study was to carry out a cross-section postal questionnaire survey dealing with musculoskeletal symptoms among female and male pig farmers in large-scale production. The participation rate overall was 70% (288/410). Over 10% of the questionnaires had missing gender data. Three different questionnaires were used: the general standardized Nordic questionnaire for the analysis of musculoskeletal symptoms; a questionnaire dealing with occurrence of numbness, reduced muscle strength, etc., in the wrists and hands; and occupational factors were screened by a special questionnaire. The results showed that musculoskeletal morbidity is high among pig farmers. The women had significantly more problems than the men with respect to the upper extremities. Symptoms in the wrists and hands such as numbness, reduced muscle strength, aching fingers and wrists, and tendency to drop things were significantly more common among the women than the men. Occupational factors dealing with, for example, the size of the pig farm, were not related to the occurrence of symptoms. Occupational factors of importance for the development of disorders, particularly among women pig farmers, should be given priority in ergonomic interventions.  相似文献   

10.
以新疆阿克苏某养猪场为案例,利用《气候变化框架公约》清洁发展机制执行理事会批准的方法（ASM III．D）,国家发改委提供的计算消耗电能的CO2排放因子参数,分析了利用沼气工程处理猪场粪便及污水和沼气发电替代化石燃料的温室气体减排潜力。结果表明,项目每年可减排温室气体49193t CO2当量,其中改变粪便管理方式减少甲烷排量占项目活动减排总量的89％,沼气发电能源替代避免的CO2排放量占减排总量的11％。项目的实施可使养殖企业每年从减排温室气体中获益502万元,使项目的投资收回年限由原来的11．5a缩短为5a。因此,如果将此类型项目开发为CDM项目,在很大程度上可提高规模化养殖企业建设沼气工程的积极性,并改善养殖企业的周边环境。  相似文献   

11.
Aeolian dust emissions can cause many environmental hazards, like accelerating land degradation and desertification, polluting air, harming human health, and so on. The dryland areas of China (DAC) are hot spots of aeolian dust emissions. To date, many efforts have been paid to researching dust emissions processes and effects, but research studies on ecosystems' function in preventing dust emissions are still very limited. In this study, we investigated the function of DAC ecosystems in preventing dust emissions, and the corresponding driving factors through integrated wind erosion modelling system (IWEMS) modelling. The main results indicate that: (1) from 2001 to 2020, the ecosystems of DAC prevented the emission of dust ~40,554 Tg, approximately 15 times as much as the total actual dust emission (~2776 Tg); (2) the function of DAC ecosystems in preventing dust emissions was relatively strong in spring and winter; (3) grassland ecosystems had the strongest function in preventing dust emissions among all the land cover types, avoiding the emission of dust ~20,857 Tg over 2001–2020; (4) dust emission prevention function provided by the DAC ecosystems benefits almost every region of China, which provides a theoretical basis for formulating ecological compensation policies; and (5) the changes in dust emissions were dominated by wind speed in most areas of DAC.  相似文献   

12.
不同耕作措施对雨养冬小麦碳足迹的影响   总被引：2，自引：1，他引：2  
为了解不同耕作管理措施对我国北方旱作农田作物生产生命周期内生产资料及生产过程碳排放足迹的影响,在山西省临汾市尧都区连续15年保护性耕作长期定位试验基地,利用静态箱-气相色谱法连续两年测定了不同秸秆管理和耕作措施(秸秆不还田旋耕、秸秆还田旋耕、秸秆覆盖免耕)下,旱作冬小麦田N_2O周年排放通量,并对不同耕作管理措施的生产资料和生产过程中的碳排放进行全面分析与计算,以估算不同耕作措施的碳足迹。结果表明:1)秸秆覆盖免耕和秸秆不还田旋耕条件下旱作冬小麦田N_2O年度累积排放量较秸秆还田旋耕分别平均减少19.2%和18.9%;2)旱作冬小麦在秸秆覆盖免耕条件下产量最高;3)旱作农田碳足迹中氮肥生产、农田N_2O直接排放和柴油消耗排放占到总排放足迹的90%以上;4)秸秆覆盖免耕较其他耕作方式的碳足迹低,两年试验期间,较秸秆还田旋耕处理碳足迹分别低11.0%和6.9%,较秸秆不还田旋耕处理碳足迹分别低7.9%和8.3%。5)在半干旱地区,秸秆覆盖免耕处理单位产量碳足迹最低,是本研究中低碳低排的推荐措施。本研究结果可为旱作农田以低碳减排为目标的可持续发展提供科学依据。  相似文献   

13.
Greenhouse gases are known to play an important role in global warming. In this study, we determined the effects of selected soil and climate variables on nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions from a tropical grassland fertilized with chicken slurry, swine slurry, cattle slurry, and cattle compost. Cumulative N2O emissions did not differ between treatments and varied from 29.26 to 32.85 mg N m-2. Similarly, cumulative CH4 emissions were not significantly different among the treatments and ranged from 6.34 to 57.73 mg CH4 m-2. Slurry and compost application induced CO2 emissions that were significantly different from those in the control treatment. The CH4 conversion factors measured were 0.21%, 1.39%, 4.39%, and 5.07% for cattle compost, chicken slurry, swine slurry, and cattle slurry, respectively, differing from the recommendations of the Intergovernmental Panel on Climate Change (IPCC). The fraction of added N emitted as N2O was 0.39%, which was lower than the IPCC default value of 2%. Our findings suggest that N2O emissions could be mitigated by replacing synthetic fertilizer sources with either biofertilizer or compost. Our results indicate the following:N2O emission was mainly controlled by soil temperature, followed by soil moisture and then soil NH4+ content; CH4 fluxes were mainly controlled by soil moisture and chamber headspace temperature; and CO2 fluxes were mainly controlled by chamber headspace temperature and soil moisture.  相似文献   

14.
猪舍环境适宜性模糊综合评价   总被引：6，自引：3，他引：3  
猪舍环境是影响猪健康水平、生长和繁殖的重要因素,对养猪生产起着决定性作用,受到广泛的关注。然而,猪舍环境是由多个环境因子相互耦合而形成的复杂的非线性时变系统。对各环境因素适宜性的描述并不是一个确定的数值,而是在一定范围内的模糊概念。目前,针对猪舍环境优劣评价大多仅限于单一环境因素,缺少基于多个环境因素的猪舍环境适宜性综合评价研究。因此,该文构建了评价指标体系和权重,根据猪舍养殖环境标准建立各环境因子的隶属度函数,提出了基于模糊集理论的猪舍多环境因子适宜性综合评价方法。以美国普渡大学 SERB 猪舍环境监测的24组数据为例对该文提出的方法进行了验证,结果表明,该文建立的猪舍环境适宜性模糊综合评价方法比单一环境因素的评价更加全面,能科学合理地反映出猪舍环境质量状况,可以很好地为猪舍环境调控提供数据参考。  相似文献   

15.
Remote sensing techniques may be one way to narrow the range of uncertainty in extrapolating N2 emissions from small-scale to large-scale terrestrial ecosystems. In the present work we investigated the correlations between denitrification activity, soil moisture, and soil thermal infrared emissions. A field experiment was performed on two different agricultural soils, one loam and one silty clay. The results indicated that thermal infrared emissions can only be used to estimate the denitrification rate in soil within a limited range of soil moisture levels. Estimates of denitrification activity based on soil texture and moisture are, however, very likely to be a fruitful approach to generating large-scale N fluxes.  相似文献   

16.
本文主要阐明猪的生产特点与畜牧工程措施之间的关系。  相似文献   

17.
猪排泄物恶臭产生与控制的微生物学原理   总被引：3，自引：1，他引：2  
猪排泄物恶臭的产生是一个涉及众多微生物的复杂过程, 研究排泄物中本土菌群的微生物组成及在恶臭产生中的作用是研制与开发有效恶臭控制技术的前提.本文从猪排泄物中主要本土菌群的组成, 不同菌群在恶臭产生中的作用, 主要恶臭化合物来源, 排泄物的重要恶臭指示物及相关的产生菌, 主要恶臭控制技术的微生物原理等角度综述了近几十年来有关猪排泄物恶臭产生与控制的研究进展.然而, 由于猪粪尿排泄物恶臭成分复杂, 影响因素众多, 且是一个主观性很强的评价指标, 有关恶臭指示物的研究仍需进一步开展和深入.此外, 猪粪尿排泄物中很多微生物是厌氧或兼性厌氧菌, 无法通过普通的平板划线法而获得纯培养, 今后应将传统的微生物厌氧培养方法与现代微生物分子生物学技术结合, 动态了解和掌握不同菌群的生长状态及在恶臭产生过程中的作用.  相似文献   

18.
Abstract

Global climate change is one of the most important issues of contemporary environmental safety. A scientific consensus is forming that the emissions of greenhouse gases, including carbon dioxide, nitrous oxide and methane, from anthropogenic activities may play a key role in elevating the global temperatures. Quantifying soil greenhouse gas emissions is an essential task for understanding the atmospheric impacts of anthropogenic activities in terrestrial ecosystems. In most soils, production or consumption of the three major greenhouse gases is regulated by interactions among soil redox potential, carbon source and electron acceptors. Two classical formulas, the Nernst equation and the Michaelis–Menten equation, describe the microorganism-mediated redox reactions from aspects of thermodynamics and reaction kinetics, respectively. The two equations are functions of a series of environmental factors (e.g. temperature, moisture, pH, Eh) that are regulated by a few ecological drivers, such as climate, soil properties, vegetation and anthropogenic activity. Given the complexity of greenhouse gas production in soils, process-based models are required to interpret, integrate and predict the intricate relationships among the gas emissions, the environmental factors and the ecological drivers. This paper reviews the scientific basis underlying the modeling of greenhouse gas emissions from terrestrial soils. A case study is reported to demonstrate how a biogeochemical model can be used to predict the impacts of alternative management practices on greenhouse gas emissions from rice paddies.  相似文献   

19.
Work in swine and poultry units is associated with exposure to significant levels of organic dust and endotoxins with the highest concentrations found in poultry houses, whereas values found in dairy and in cattle farming are much lower. Corresponding to this is an excess of work-related respiratory symptoms in swine farmers. A dose-response relationship exists between symptoms and number of working hours. Longitudinal studies have demonstrated an accelerated decline of lung function in swine farmers large enough to cause clinically significant disease in some farmers. Because of the large number of people needed in swine farming and the long working hours, swine farming has emerged as the major respiratory problem in farming. Experimental studies indicate that exposure has to be lowered substantially to avoid acute effects and longitudinal studies demonstrate that loss of lung function occurs in non-smoking swine farmers without respiratory symptoms and that accelerated decline in lung function occurs below endotoxin concentrations in dust (100 ng/m3) proposed as a safe threshold.  相似文献   

20.
中国农业温室气体排放量测算及影响因素研究   总被引：3，自引：0，他引：3  
农业生产过程所产生的温室气体在全球生产活动温室气体排放总量中占有很大比例,因此对农业温室气体的排放量进行测算并分析其影响因素,对实现农业节能减排有重要意义。本文基于1993―2011年中国农业生产的相关统计数据,借鉴前人关于农业生产中各种温室气体排放源排放系数的研究成果,测算了中国农业生产过程中的CH4、N2O和CO2排放量,并分析了影响因素。结果表明,CH4排放量基本平稳波动不大,N2O排放量从1993年的93.21万t波动增加到2011年的120.51万t,农业生产资料CO2排放量由15 626.98万t增加到31 258.10万t。种植业CO2排放主要分为土壤排放和生产资料排放,土壤CO2排放与大气温度、土壤温度、地表温度和土壤水分有关,生产资料CO2排放主要是由化肥和农药造成的;种植业CH4、N2O排放原因较为复杂,还有待进一步研究;动物肠道发酵CH4、N2O排放的影响因素主要取决于动物种类、饲料特性、饲养方式和粪便管理方式等。  相似文献   

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