气溶胶雾滴粒径和灭蚊蝇功效的实验研究

实验室内用气雾雾化框产生不同大小的雾滴谱,观察其与灭蚊、蝇效果的关系。实验发现(1)喷雾压力与雾滴粒谱呈负相关(r=-0.9894,p<0.01,压力增大时,雾滴减小;(2)模型Y=A BX CX~2适于描述雾滴粒径与生物效果之间关系;(3)室内防制家蝇的最佳雾滴粒径为7.9～0.2μNMD,防制淡色库蚊的最佳雾滴粒径为3.3～9.2μNMD。     

介绍一种雾化吸入治疗矽肺用的设备——CW—1型超声波雾化器

一、概述: 超声波雾化器是应用超声波的声能将水分及药液变成微细的气溶胶,随着患者的呼吸过程进入呼吸道。其特点是雾量大,雾滴小而均匀、能深达支气管及肺泡,且雾量大小不受气量限制。对于应用克矽平雾化吸入疗疗矽肺提供了一种比较先进的医疗器械。二、结构及工作原理: CW-1型超声波雾化器是由超声波信号发生器、压电晶体换能器和雾化罐三部分组成。仪器的面     

衢州市蚊蝇密度监测及防治效果分析

目的通过对衢州市城区蚊、蝇种群和密度监测,分析衢州市蚊、蝇防治效果。方法采用诱蚊灯法监测蚊密度,笼诱法监测蝇密度。结果衢州市城区蚊类有3属4种,淡色库蚊为优势种,占捕蚊总数的96．82％,年平均成蚊密度为5．28只／（灯·h）,6—8月为高峰期。城区蝇类有4科6属,绿蝇属和家蝇属为优势种群,分别占68．22％和23．82％,年平均蝇密度39．74只／笼,蝇密度高峰在6—8月。结论2005--2010年衢州市城区采用综合防治措施,有效地控制了蚊、蝇孳生地,密度指数明显下降,达到预期效果。     

2009—2015年丹阳市蚊蝇密度监测

目的了解丹阳市蚊蝇种群构成和季节消长情况,为蚊蝇的科学防治提供依据。方法蚊密度监测采用诱蚊灯法,蝇密度监测采用笼诱法。结果 2009—2015年共捕获成蚊7 350只,平均蚊密度为0.44只/(灯·h),淡色库蚊为优势种,占90.11%。不同年份蚊密度差异无统计学意义,全年消长呈双峰型,活动高峰出现在7月和10月;共捕获蝇1 879只,平均蝇密度为2.68只/笼;家蝇和麻蝇为优势种,分别占27.35%和26.98%。自2009年,蝇密度逐年升高,至2013年出现高峰,此后密度下降,全年消长呈单峰型,活动高峰出现在7月。结论 2009—2015年,丹阳市蚊蝇密度整体均处于较低水平,但蝇密度在个别年份存在反弹现象,提示应充分利用蚊蝇密度监测结果,科学指导蚊蝇防治工作,并逐步建立和完善蚊蝇防治长效机制。     

2008—2012年汕头市病媒生物监测结果分析

目的通过对汕头市病媒生物的监测,了解2008—2012年汕头市蚊、蝇、鼠和蜚蠊的种类和消长情况,为汕头市病媒生物防治及其传播疾病的控制提供依据。方法成蚊密度监测采用诱蚊灯法,蝇密度监测采用笼诱法,鼠密度监测采用夹夜法,蜚蠊密度监测采用粘蟑纸法,均为全年监测。结果 2008—2012年汕头市成蚊密度分别为17.02、6.53、14.45、16.23和27.25只/灯,以致倦库蚊为优势蚊种,占91.89%（8 986/9 779）;蝇密度5年分别为20.97、12.20、4.89、4.08和3.43只/笼,以家蝇为优势种群,占71.97%（2 362/3 282）;鼠密度5年分别为0.61%、0.18%、0.10%、0.14%和0.11%,以褐家鼠为优势鼠种,占92.00%（69/75）;蜚蠊密度5年分别为1.11、0.49、0.26、0.33和0.39只/张,以德国小蠊为优势种群,占79.10%（1 052/1 330）。蚊类活动高峰期在3—6月,其中5月密度最高,为33.44只/灯;蝇类活动高峰期在3—5月,其中4月密度最高,为15.3只/笼;鼠类活动高峰期为4月,密度为0.66%;蜚蠊活动高峰期在5—7月和9月,其中6、7月密度最高,为0.87只/张。结论致倦库蚊、家蝇、褐家鼠、德国小蠊是汕头市主要防制的病媒生物种类,要降低其密度,应根据它们的孳生、栖息习性及其季节消长特点,采取以环境治理为主的综合性防治措施。     

2022年南通市通州区病媒生物监测结果分析

目的了解2022年通州区主要病媒生物种群构成、密度及季节消长规律,为病媒生物防制工作提供科学依据。方法采用诱蚊灯法、笼诱法、夹夜法、粘捕法,对蚊、蝇、鼠、蟑螂进行监测。结果2022年3—11月蚊类监测平均密度为24.88只/(灯·夜),6—8月密度最高,占69.25%;优势种为淡色库蚊,占75.30%;不同生境中牲畜棚蚊密度最高,为82.64只/(灯·夜)。3—11月蝇类监测平均密度为4.65只/笼,7月达到最高峰,密度为8.88只/笼;优势种为家蝇,占33.73%;不同生境中农贸市场蝇密度最高,为6.94只/笼。全年共捕获鼠类6只,鼠类密度为0.33%。鼠类密度季节消长变化不明显;不同生境中农村居民区捕获4只(占66.67%),占比最高。蟑螂密度为0.18只/张,均为德国小蠊,全年均有活动,密度季节消长情况不明显,超市和农贸市场密度较高,分别为0.45只/张和0.42只/张。结论通过监测初步掌握了通州区病媒生物种群构成、密度、季节消长规律,可为防制工作提供相关参考。     

诱蚊诱卵器监测法在花园蚊媒监测中的应用

目的分析某花园2016年3—11月诱蚊诱卵器监测情况,并探讨诱蚊诱卵器监测法在白纹伊蚊密度监测中的适用性。方法于2016年3—11月在花园内布放诱蚊诱卵器,每个监测点诱卵器之间的距离在25m以上,并与传统指标进行相关性分析。结果共布放1 800个诱蚊诱卵器,回收1 663个,有效1 643个,阳性314个,诱蚊诱卵器指数为19.11。其中5月最高,10月最低,差异有统计学意义(χ2=326.88,V=8,P0.05)。诱蚊诱卵器指数与成蚊密度具有相关性(R=0.63,P=0.020.05);与标准间指数无相关性(R=0.03,P=0.920.05)。结论诱蚊诱卵器监测法在花园的伊蚊密度监测中发挥重要作用,是登革热应急监测中不容忽视的一种监测方法。     

盐城市盐都区2013年病媒生物密度监测

目的了解病媒生物种群、密度分布及季节消长规律,为制定防制措施提供依据。方法 2013年采用夜夹法监测鼠密度,用诱蚊灯法监测蚊密度,用笼诱法监测蝇类,用蟑螂屋诱捕法监测蟑螂,记录并统计监测结果。结果盐城市盐都区全年鼠密度为0.41%,褐家鼠为优势鼠种(占70.00%),3月鼠密度最高,为0.99%。4—11月蚊虫活动期间,蚊密度为0.559只/人工小时,淡色库蚊为优势蚊种(占47.9%),6—8月为蚊密度高峰期,占捕蚊总数的76.63%。4—11月蝇活动期间,蝇密度为8.15只/笼,家蝇为优势蝇种(占52.15%),5—8月为蝇密度高峰期,占捕蝇总数的90.80%。全年均未捕获到蟑螂。结论经常开展卫生宣传,搞好环境治理,消除孳生地,是消灭"四害"工作的重点。     

2016年安徽南部洪灾后重要病媒生物应急监测

目的了解安徽南部洪灾后重要病媒生物的种类、密度、分布及消长规律。方法分别采用夹夜法、诱蚊灯法和笼诱法开展鼠、蚊和蝇类监测。结果共布放2 152只次鼠夹,有效夹2 042只,捕获鼠类34只,捕获率为1.67%;鼠类捕获率与日均气温呈极显著正相关关系(R=0.996,P0.01)。洪灾区钩体病月病例数与鼠密度间呈极显著正相关关系(R=0.995,P0.01),出血热月病例数与媒介黑线姬鼠密度间也呈显著正相关关系(R=0.972,P0.05)。布放诱蚊灯60盏次,捕获雌性成蚊3 084只,属于蚊科3属7种,蚊密度为51.4只/(灯·夜),优势蚊种为三带喙库蚊;灾区蚊密度与日均气温呈极显著正相关关系(R=0.996,P0.01)。共布放诱蝇笼57只,捕获成蝇224只,属于6科12属14种,蝇密度为18.67只/笼,优势种为家蝇等。结论洪灾后卫生防疫的重点为鼠、蚊、蝇类防治。     

2015年南京市病媒生物监测分析

目的了解2015年南京市主要病媒生物(蚊、蝇、蟑螂、鼠)的种类、密度及季节消长情况,为有效预防和控制病媒生物性传染病的发生和流行提供参考。方法按照《全国病媒生物监测方案(试行)》要求,开展重要病媒生物(蚊、蝇、蟑螂、鼠)监测,分别采用诱蚊灯法、笼诱法、粘捕法、夹夜法。结果 2015年南京市蚊密度为0.82只/h,主要蚊种为三带喙库蚊和淡色库蚊;蝇密度为1.20只/笼,主要蝇种为家蝇、棕尾别麻蝇和丝光绿蝇;蟑螂密度为1.40只/张,蟑螂种类为德国小蠊和黑胸大蠊;鼠密度为0.055%,种类为褐家鼠和黄胸鼠;季节消长情况为蚊蝇密度呈单峰型,峰值出现在7月;蟑螂密度呈双峰型,峰值出现在7月和9月。结论2015年南京市蚊、蝇、蟑螂和鼠密度相比2014年均显著下降。     

城市室内蟑螂化学防制方法研究

目的观察不同施药方式对室内蟑螂的防制效果,探索城市室内蟑螂化学防制方法。方法采用药激法观察施药前后的蟑螂密度变化。结果热烟雾技术防制室内蟑螂,即时杀灭率平均可达97.31%,在不采取任何后续维护性防制措施情况下,第30、60天的杀灭率分别是89.31%和56.95%,第90天蟑螂密度会达到或超过防制前水平。在使用热烟雾技术的同时进行滞留喷洒,其效果同单纯使用热烟雾处理基本相同。胶饵剂防制室内蟑螂,施药后第3天的杀灭率为46.23%,第30、60和90天的杀灭率分别是98.13%、97.49%、98.28%。胶饵剂作为热烟雾处理后的巩固措施,30、60、90 d的杀灭率分别是98.96%、97.61%、98.94%。结论热烟雾技术防制室内蟑螂,见效快,无持效性。胶饵剂见效慢,持效时间长。采用胶饵剂作为速杀后的巩固手段,具有良好效果。     

Evaluation of pyrethrin and permethrin ground ultra-low volume applications for adult Culex control in rural and urban environments of the Coachella Valley of California

Six experimental ground ultra-low volume (ULV) applications of Pyrenone 25-5 (0.0025 lb/acre) and Aqua-Reslin (0.007 lb/acre) were made by truck-mounted Pro-Mist or London Fog equipment over 1-mi2 study areas in rural and residential environments of the Coachella Valley, Riverside County, California. Efficacy of replicate applications was evaluated by measuring mortality among caged sentinel mosquitoes, by evaluating changes in host-seeking abundance at replicated dry ice-baited traps positioned along intersecting east-west and north-south transects, and by differential recapture patterns of marked females released near traps in the sprayed central core and unsprayed control areas. Sentinel mortality agreed well with estimates of droplet density measured by "slide spinners" and was affected by 1) distance of cages from the truck route; 2) landscape features, such as tree lines that created wind shadows; 3) irregular landscape that disrupted the particle cloud; 4) low wind speed that failed to carry the droplet cloud through the environment; and 5) failure of the droplets to penetrate dead airspace within stands of vegetation. Despite variable sentinel mortality, Culex tarsalis relative abundance in rural landscapes within and around our study areas always declined after ULV applications. Concurrent decreases in abundance at traps within sprayed and adjoining unsprayed areas confounded our estimates of percentage of control using Mulla's formula, which compares abundance in sprayed and unsprayed areas pre- and postspray. ULV applications significantly affected recapture patterns, in that recapture rates within the spray zone usually were significantly less than in the unsprayed zone. Collectively, our data indicated that ground ULV applications measurably reduced Cx. tarsalis abundance in rural areas of the Coachella Valley but that further evaluations may be necessary to validate efficacy on Culex quinquefasciatus populations in residential communities.     

Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises

The epidemics of severe acute respiratory syndrome (SARS) in 2003 highlighted both short- and long-range transmission routes, i.e. between infected patients and healthcare workers, and between distant locations. With other infections such as tuberculosis, measles and chickenpox, the concept of aerosol transmission is so well accepted that isolation of such patients is the norm. With current concerns about a possible approaching influenza pandemic, the control of transmission via infectious air has become more important. Therefore, the aim of this review is to describe the factors involved in: (1) the generation of an infectious aerosol, (2) the transmission of infectious droplets or droplet nuclei from this aerosol, and (3) the potential for inhalation of such droplets or droplet nuclei by a susceptible host. On this basis, recommendations are made to improve the control of aerosol-transmitted infections in hospitals as well as in the design and construction of future isolation facilities.     

Adsorption of polycyclic aromatic hydrocarbons at the air-water interface and its role in atmospheric deposition by fog droplets

This review addresses the significance of air-water interfacial adsorption in the fate and transport of polycyclic aromatic hydrocarbons (PAHs) in dispersed systems, such as fog droplets in the atmosphere and air bubbles in wastewater systems. The equilibrium (partition constants) and transport (mass accommodation coefficients) parameters in dispersed systems are discussed. Specific cases where the air-water interfacial adsorption makes a significant impact, such as uptake of naphthalene by fog droplets in a falling droplet reactor and of pyrene removal on air bubbles in a solvent sublation reactor, are discussed as illustrations. The consequence of the air-water interface in atmospheric wet deposition of PAHs by fog droplets is analyzed mathematically.     

Impact of electrostatic and conventional sprayers characteristics on dispersion of barrier spray

A study was conducted to analyze the performance of 3 electrostatic (Electrolon BP-2.5, Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and 2 conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in an enclosed area. Sprayer characteristics such as charge-mass ratio, air velocity, flow rate, and droplet spectra were measured while spraying water. Dispersion of the spray cloud from these sprayers was determined using coverage on water-sensitive cards at various heights (0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, and 3.0 m) and depths (1 m, 3 m, and 5 m) into the under-forest vegetation while spraying bifenthrin (Talstar 7.9% AI; FMC Corporation, Philadelphia, PA) at the rate of 21.8 ml/300 m of treated row. The charge-mass ratio data show that Electrostatic head on a Stihl 420 did not impart enough charge to the droplets to be considered as an electrostatic sprayer. In general, the charged spray cloud moved down toward the ground. The Electrolon BP 2.5 had significantly lower spray coverage on cards, indicating lack of spray dispersion. This sprayer had the lowest air velocity and did not have the air capacity needed to deliver droplets close to the target for electrostatic force to affect deposition. The analysis shows that these 2 sprayers are not a suitable choice for barrier sprays on vegetation. The results indicate that the Buffalo Turbine is suitable for barriers wider than 3 m, and the Spectrum 4010 and Stihl 420 are suitable for 1-3-m-wide barriers.     

Modeling studies of the concurrent growth and neutralization of sulfuric acid aerosols under conditions in the human airways

A kinetic model of coupled droplet growth, gas uptake, and chemical reaction has been used to examine the possible changes to sulfuric acid aerosols as a result of exposure to respiratory ammonia under the conditions in the human airways. Results for a wide range of initial droplet sizes and concentrations spanning the extremes of likely atmospheric conditions are presented. It is predicted that gas phase reactions of SO2 will not significantly affect the neutralizing capability of airways ammonia. The effects of physical and chemical parameters on aerosol neutralization and growth are discussed and in particular, predictions of neutralization in typical inhalation times for aerosols characteristic of severe persistent London fogs and modern urban conditions are compared. The analysis supports the suggestion that the London fog episodes were unique in the relationship of the acid droplets formed to the neutralizing capability of ammonia in the human airways and that simple extrapolation of mortality and morbidity data from such episodes to modern conditions is unlikely to be valid.     

Unique cellular and humoral immunogenicity profiles generated by aerosol,intranasal, or parenteral vaccination in rhesus macaques

Respiratory mucosa immunization is capable of eliciting both local and distal mucosal immune responses; it is a potentially powerful yet largely unused modality for vaccination against respiratory diseases. Targeting the lower versus upper airways by aerosol delivery alters the immunogenicity profile of a vaccine, although the full extent of this impact is not well characterized. We set out to define the cellular and humoral response profiles elicited by immunization via intranasal, small aerosol droplets, and large aerosol droplets. We compared responses following adenovirus-vectored vaccination by these routes in macaques, either for the generation of primary immune responses or for the boosting of previously primed systemic responses. Aerosol delivery (4 or 10 μm diameter droplets, addressing lower or upper airways, respectively) generated the highest magnitude lung CD4 and CD8 T-cell responses, reaching 10–30% vaccine-specific levels in bronchoalveolar lavage cells. In contrast, intranasal delivery was less immunogenic with >10-fold lower peak lung T-cell responses. Systemic (blood) T-cell responses were only observed following 4 μm aerosol (and parenteral) immunization, while all delivery routes elicited similar humoral responses. These data demonstrate distinct immune response profiles with each respiratory tract vaccination modality and suggest that small droplet aerosol offers several immunological advantages over other respiratory routes.     

Effects of pressure and flow rate on Cythion droplet size produced by three different ground ULV aerosol generators

A study to determine the effects of machine pressure and insecticide flow rate on the size of aerosol droplets as they relate to the Cythion label was conducted with 3 different ground ULV aerosol generators. An increase in flow rate required a corresponding increase in blower pressure to maintain the labeled droplet mass median diameter of 17 microns or less. Droplets larger than 48 microns were frequently sampled at machine pressures less than 6 psi (41.4 kPa). At the highest labeled flow rate of 8.6 fl oz/min (254.3 ml/min), machine pressures of 7-8 psi (48.3-55.2 kPa) were required for each of the 3 aerosol generators tested to consistently conform to the droplet criteria of the Cythion label.     

Evaluation of naled applied as a thermal fog against Culicoides furens (Diptera: Ceratopogonidae)

Naled/diesel oil (1:99), applied as a thermal fog, was tested against the biting midge Culicoides furens. The insects were confined in small cages suspended at 4 heights on poles at progressively greater distances from the fog release point. In terms of population survival 24 hr after treatment, a parabolic equation accurately described the regression of percent survival on distance from the release point. If 10% survival is considered as the maximum acceptable, then the equation predicts adequate control up to 19.6 m (64.3 ft) from the fog release point.     

Comparison of dilute and neat formulations of Anvil by ultra-low volume ground application against Anopheles quadrimaculatus in Arkansas

Neat (undiluted) and diluted ground-applied ultra-low volume (ULV) cold aerosol formulations of sumithrin (Anvil) were evaluated against Anopheles quadrimaculatus adults. Both formulations were applied at 1.938 g/AI/ha (0.00173 lb/AI/acre). Caged sentinel mosquitoes were placed on 1.5-m stakes 30.4, 60.9, and 91.0 m downwind and perpendicular to the line of spray. Mortality was observed at 1, 12, and 24 h posttreatment. Except for 1-h readings at 30.4 and 91.0 m the neat formulation was significantly more effective than the dilute. Droplet size and density averaged 13.6 microm and 422/cm2 for dilute formulation and 14.3 microm and 251/cm2 for the neat. There was no apparent relationship between droplet size and density when compared with mosquito mortality.