Firefighting efforts may lead to massive fungal growth and exposure within one week. A case report

A case study on extensive fungal growth that occurred in an apartment building after firefighting efforts is described in this paper. Exposure to airborne microorganisms (both viable and total) was investigated by filter sampling in three periods before and during remedial actions after the fire. Material samples were also analyzed. Extensive mold growth was observed on the building materials as soon as eight days after the fire. High concentrations of fungal spores, 10(7) cfu/g, were found when material samples were analyzed. Concentrations of airborne fungal spores (10(4) spores/m3) were also high and increased by two orders of magnitude during the demolition of moldy building materials and during the clean-up after the demolition. The proportions of airborne viable fungi in comparison with the total spore concentrations were 28-83% immediately after the fire, but they had decreased to <1% two months after the fire during the reconstruction phase. Paecilomyces was the main fungal genus in the indoor air before and during the demolition, while Penicillium dominated during the reconstruction. Paecilomyces was not detected in the outdoor air. Paecilomyces and Penicillium were also found in the material samples. The results show that fast and extensive mold growth in a building may take place also in subarctic climates, at least during summer. High concentrations of fungal spores are released to the air during the demolition of moldy building materials and the following clean-up. Therefore, personal protection is necessary during such work.     

The isolation of Campylobacter spp. from modified atmosphere packaged foods

Foodborne illness caused by Campylobacter spp. is a major public health concern in many countries. This study investigated the prevalence of Campylobacter spp. in modified atmosphere packaged (MAP) foods such as fresh meat and vegetables in order to assess the risk to human health from foods packaged using this new technology, the application of which is increasing rapidly. Samples of MAP chicken meat, MAP turkey meat, MAP bacon and MAP mixed salad vegetables from two supermarkets were tested for the presence of the organism in two types of samples; those tested immediately on purchase and those stored at 4 C (+/- 2 C) and subsequently tested on the 'use by' date stated on the package. Campylobacter spp. were found to be present in a proportion of all MAP products tested: 90% of MAP turkey samples, 71.25% of MAP chicken samples, 67.5% of cured bacon samples and 22.2% of mixed salad vegetables samples were found to be contaminated with Campylobacter spp. Viable counts indicated that the level of infection varied both between food products and between different packages of the same product. Turkey meat was found to have the highest numbers of organisms present (5.2 102-3.3 103 cfu g-1) compared with 0.2-7.2 102 cfu g-1 for chicken meat and 0.1-3.1 102 g-1 for bacon. The highest count obtained from one sample of salad vegetables was 1.7 102 cfu g-1 with the majority (16 out of a total of 20 positive samples) being less than 0.8 102 cfu g-1 and all 12 of the positive samples tested on date of purchase having viable counts of less than 0.1 102 cfu g-1.     

Food-associated bacteria in bioaerosols of delicatessens

Air constituency of the delicatessen sections of a retail group was assessed for the presence and distribution of bioaerosols and the correlation with physical parameters. Total viable counts were determined and the total coliforms, Escherichia coli, other members of the Enterobacteriaceae and Staphylococcus aureus were enumerated. These counts were relatively low, with the average total viable counts 1.34x102 cfu . m-3, Enterobacteriaceae 2.6x10 cfu . m-3 and S. aureus 2.2x10 cfu . m-3. Small numbers of total coliforms were detected and E. coli was not present at all. The distribution of Enterobacteriaceae differed significantly between three groups of visitor numbers and the total viable counts differed between two types of ventilation. The risk of infection should not be disregarded as a result of finding these organisms only in small numbers and could be a starting point in the prevention of food contamination, by regulating mechanisms to effectively minimize bioaerosols counts of enteric bacteria.     

Characterization of exposure to molds and actinomycetes in agricultural dusts by scanning electron microscopy, fluorescence microscopy and the culture method

Air samples from 79 farms with 10(5) to 10(11) microorganisms/m3 were analyzed by scanning electron microscopy (SEM), fluorescence microscopy (FM), and the culture method. The total exposure to microorganisms (particularly actinomycetes) was underestimated when assessed as colony-forming units (cfu). The average cfu count was one-sixth of the total count according to SEM or FM, and the individual variability was great. This occurrence was partly explained by the aggregation of spores. Single spores accounted for 2-65% of all spores in 35 samples. There was an average of three spores/particle, and 93 (range 67-100)% of the spores were single or in aggregates of respirable size. Aggregation was more pronounced for actinomycetes and at high spore counts. Actinomycetes and bacteria could not be distinguished by FM. Bacteria (other than actinomycetes) were not detected by SEM, yet the total count of microorganisms was similar for FM and SEM. Most particles were spores from actinomycetes and fungi of the genera Aspergillus or Penicillium.     

Impact of portable air filtration units on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions

We undertook a one-year study to investigate the impact of the NSA model 7100A/B portable air filtration unit on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions. Weekly measurements for airborne A. fumigatus were conducted in indoor and outdoor air, and surveillance for invasive aspergillosis was based on a combination of ward liaison, targeted chart review and consultation with the medical staff. The mean indoor A. fumigatus counts (8.1 cfu/m3; range, <0.8 to 42 cfu/m3) reflected the fungal load of outdoor air (9.4 cfu/m3; range, <0.8 to 50 cfu/m3), and were reduced by only about one third in rooms with portable air filtration units (5.3 cfu/m3; range, <0.8 to 41 cfu/m3). During the study period, a total of five cases (incidence density, 0.8 per 1000 patient-days) of invasive aspergillosis (one proven case, four suspected cases; case fatality rate 40%) were recorded. None of these five patients was allocated to a room with portable air filtration unit, however, the difference between incidence densities in rooms with and without portable air filtration units was non-significant (Fisher's exact test, P=0.33). Due to the noise level and thermal discomfort, patient compliance with the air filtration units was poor. We conclude that under field conditions this air filtration unit cannot be recommended for prevention of invasive aspergillosis in neutropenic haematology-oncology patients.     

Fungi carried from farmers' work into farm homes

Airborne fungal spore concentrations and main fungal genera were compared in rural and urban living environments in Finland during the winter. In addition to conventional viable fungal spore counts (based on the six-stage impactor sampling and cultivation), total spore concentrations were obtained by scanning electron microscope (SEM) investigation of filter samples. The viable spore counts were only 0.2%-25% of the number of total spore aggregates. A high correlation between these two methods was noted, however, at the recommended measuring ranges of the methods. In the farm houses, viable and total spore levels were 10(3) to 10(4) colony forming units/m3 (cfu/m3) and 10(4) to 10(5), spores/m3, respectively. These counts were 10-10(3)-fold higher than the concentrations in an urban apartment. The spore levels of farmers' homes, however, were somewhat lower than those observed in their cow barns. Aspergillus, Cladosporium, and Penicillium spores were present in both urban and rural environments. Actinomycetes and some fungal genera--such as Acremonium, Alternaria, Botrytis, and Chrysosporium--which were detected in cow barns and in farm houses, were not present in urban environment. The results indicated that airborne fungal spores may be carried from cow barns to farmers' homes.     

Airborne mold and endotoxin concentrations in New Orleans, Louisiana, after flooding, October through November 2005

BACKGROUND: The hurricanes and flooding in New Orleans, Louisiana, in October and November 2005 resulted in damp conditions favorable to the dispersion of bioaerosols such as mold spores and endotoxin. OBJECTIVE: Our objective in this study was to assess potential human exposure to bioaerosols in New Orleans after the flooding of the city. METHODS: A team of investigators performed continuous airborne sampling for mold spores and endotoxin outdoors in flooded and nonflooded areas, and inside homes that had undergone various levels of remediation, for periods of 5-24 hr during the 2 months after the flooding. RESULTS: The estimated 24-hr mold concentrations ranged from 21,000 to 102,000 spores/m3 in outdoor air and from 11,000 to 645,000 spores/m3 in indoor air. The mean outdoor spore concentration in flooded areas was roughly double the concentration in nonflooded areas (66,167 vs. 33,179 spores/m3 ; p < 0.05) . The highest concentrations were inside homes. The most common mold species were from the genera of Cladosporium and Aspergillus/Penicillium ; Stachybotrys was detected in some indoor samples. The airborne endotoxin concentrations ranged from 0.6 to 8.3 EU (endotoxin units) /m3 but did not vary with flooded status or between indoor and outdoor environments. CONCLUSIONS: The high concentration of mold measured indoors and outdoors in the New Orleans area is likely to be a significant respiratory hazard that should be monitored over time. Workers and returning residents should use appropriate personal protective equipment and exposure mitigation techniques to prevent respiratory morbidity and long-term health effects.     

Lung function and precipitating antibodies in low exposed wood trimmers in Sweden.

Wood trimmers are exposed to molds that periodically grow on timber that may induce alveolitis and obstructive lung disease. We have evaluated respiratory symptoms, bronchial reactivity, and lung function in 28 wood trimmers at a Swedish sawmill and in 19 unexposed office workers. Eleven (sero-positive) of the wood trimmers had precipitating antibodies in peripheral blood against one or several molds. The exposure to dust (median 0.26 mg/m3), viable mold spores (median 2950 cfu/m3), viable bacteria (median 370 cfu/m3), airborne endotoxins (range 0.0015-0.0025 microgram/m3), and terpenes (range 0.4-23 mg/m3) was lower than levels that earlier have been reported to affect lung function. The wood trimmers reported an increased prevalence of cough and breathlessness. They also showed signs of a mild obstructive impairment with a tendency to increase bronchial sensitivity to metacholine and decreased FEV1 after 2 days free from exposure. FEV1 decreased more during the working week in the sero-positive workers than among the sero-negative workers, and for the whole group the decrease in FEV1 and MEF25 was correlated to the degree of mold exposure.     

地下空间空气中微生物调查

目的通过对51个地下空间空气中微生物检测,了解地下空间空气中微生物污染状况.方法1992-2004年对华北地区51个地下空间,按通风状况分为密闭型(12个)、通风型(21个)、半密闭型(18个).用撞击法和沉降法检测空气中细菌总数、真菌数、链球菌及厌氧菌.分离出的黄曲霉菌用ELISA方法检测黄曲霉毒素B1.结果地下空间空气中细菌总数符合GJB 3768-1999《屯兵坑道环境卫生学要求》,半密闭型地下空间房间和通道空气中细菌总数、真菌数的监测结果均高于相应对照(P＜0.01).鉴定出的2 845株真菌中,青霉属及曲霉属为优势菌,分别占41.5%及19.1%.73株黄曲霉菌中黄曲霉毒素B1阳性者9株,占12.3%.通风型、密闭型地下空间通道和房间空气中厌氧菌高于相应对照组(P＜0.01或P＜0.05),链球菌与相应对照组相比,差异无统计学意义.密闭型通道空气中厌氧菌分别是半密闭型及通风型通道的4.2倍及3.8倍.结论地下空间房间和通道空气中含有大量真菌和厌氧菌,对进驻人员健康有一定危害.     

生物垃圾加工厂供料厅空气微生物菌群的研究

[目的]为了减少环境污染与公害,对生物垃圾加工厂供料厅的空气细菌菌群及其含量进行研究。[方法]使用ANDERSEN-空气微生物收集器和KS-92(Impinger)喷冲器对上述地点在5个日期两个采样点收集了157个空气样品,在3个测量日期采集生物垃圾样品102个。[结果]空气中需氧菌总数浮动于4.62×103～9.55×105CFU／m 3之间;厌氧菌为3.07×103～2.14×104CFU／m 3,其中魏氏梭菌含量 为1.1～197 CFU／m 3,气悬状态的魏氏梭菌以孢子形式存在。[结论]空气微生物气溶胶的含量与菌源距离呈反比,空气中菌群和含量能作为生物垃圾污染与质量的指示。     

Correlation between surface and air counts of particles carrying aerobic bacteria in operating rooms with turbulent ventilation: an experimental study.

Airborne contamination with bacteria-carrying particles (cfu/m3) and their sedimentation rate (cfu/m2/h) was compared in an operating room (OR) equipped with two turbulent ventilation systems. One was a thermally based system with inlet of cool clean air at the floor level and evacuation of the air at the ceiling by convection (17 air changes/h). The other was a conventional plenum pressure system with air supply at the ceiling and evacuation at the floor level (16 air changes/h). The study was made during rigidly standardised sham operations (N = 20) performed in the same OR by the same six member team wearing non-woven disposable or cotton clothing. Airborne contamination in the wound and instrument areas was related to the surface contamination rate in the same areas and in addition, on the patient chest and in the periphery of the OR. With the exception of the periphery of the OR, the surface and air contamination rates were highly correlated in both ventilation systems (P = 0.02-0.0006, r2 = 0.52-0.79). This was also true particularly when disposable clothing was used while the correlation was weaker in cotton clothing experiments. An equation describing the relation between surface and air counts is given. Typically, the surface counts were numerically 16-fold the air counts, i.e., the number of colonies sedimenting on four 14 cm-diameter agar plates during 1 h will almost equal the number of airborne cfu per m3. We propose, that sedimentation plates represent not only a technically easier method than air sampling but when correctly used, are also the most realistic indicator of airborne bacterial OR contamination in areas critical for surgery.     

医院室内空气细菌污染的调查

目的 了解医院室内空气细菌污染状况。方法 2002年6月在浙江某城市医院6个科室及室外用沉降法距地面1.5m高度采空气样，每周1d，每天2次，连采3周。用GB9671-1996的医院候诊室卫生标准和GB15982-1995的Ⅲ类环境空气卫生标准来评价室内空气细菌污染状况。结果 候诊室，输液室，换药室，儿科病房，内科病房，办公室和医院室外空气细菌总数分别为5.9-27.4,2.3-11.0,0.9-11.2,3.3-8.0,2.4-9.7,2.5-8.0和4.6-25.7cfu/皿，空气溶血性链球菌及草绿色链球菌分别为0.6-2.4,0.4-1.3,0-0.5,0.1-0.5,0.2-0.5,0-0.7和0.1-2.5cfu/皿，且各采样点均检出β溶血细菌，结论 该医院室内空气溶血性链球菌及草绿色链球菌的污染应引起重视。     

Indoor health: background levels of fungi

There is no uniformity in the suggested guidelines for acceptable levels of fungi in indoor ambient air. Thus, health professionals have no way to determine what levels of fungi may pose a threat to human health. The authors reviewed the published literature to identify data reported for noncomplaint structures, that is, structures in which occupants did not have health concerns associated with the quality of the indoor air. For both commercial and residential structures, fungal concentrations detected were often higher than currently suggested guidance values. The average indoor air concentration in 149 noncomplaint commercial buildings was 233 colony forming units (CFU) per cubic meter, whereas outdoor ambient air levels averaged 983 CFU/m(3). Total indoor spore counts ranged from 610 to 1040 spores/m(3) in three commercial buildings. Outdoor total spore counts associated with these buildings ranged from 400 to 80,000 spores/m(3). The average indoor concentration reported for 820 noncomplaint residential structures was 1252 CFU/m(3) with an average outdoor level of 1524 CFU/m(3). Total spore counts detected indoors at 85 residential structures ranged from 68 to 2307 spores/m(3). Outdoor spore levels associated with these structures ranged from 400 to 80,000 spores/m(3). A large proportion of both commercial and residential noncomplaint structures have indoor ambient air fungal concentrations above 500 CFU/m(3), a level often advocated as requiring remediation in structures when occupants complain of nonspecific adverse health symptoms.     

人员活动和空气净化器对支气管镜室空气微生物和颗粒物的影响

目的评价人员活动和空气净化器对支气管镜室空气微生物及颗粒物的影响。方法依照支气管镜室有无人员活动和空气净化器,将实验分成四组:动态无净化组、动态净化组、静态无净化组、静态净化组,在五个不同时间点(0、0.5、1、2、4 h)对室内空气进行采样和分析,用浮游菌法采集空气中的微生物并培养、计数,用DT-9881M激光尘埃粒子计数器检测颗粒物浓度,统计方法采用析因设计的方差分析。结果动态无净化组的细菌、真菌、总微生物(细菌+真菌)、PM_(2.5)和PM_(2.5~10.0)菌落数/浓度分别为(113.53±7.78)CFU/m~3、(89.67±7.17)CFU/m~3、(203.20±10.92)CFU/m~3、(86 557.20±4 158.29)个/m~3和(659.69±38.91)个/m~3,静态无净化组分别为(84.33±3.65)CFU/m~3、(65.00±2.65)CFU/m~3、(149.33±4.98)CFU/m~3、(45 812.64±1 279.61)个/m~3和(189.15±4.64)个/m~3,动态净化组分别为(84.80±8.08)CFU/m~3、(90.40±5.50)CFU/m~3、(175.20±9.22)CFU/m~3、(49 336.38±2 039.16)个/m~3和(218.36±7.02)个/m~3,静态净化组分别为(67.80±5.63)CFU/m~3、(38.27±3.70)CFU/m~3、(106.07±6.76)CFU/m~3、(29 772.53±2 212.93)个/m~3和(124.80±7.16)个/m~3,细菌、总微生物、PM_(2.5)、PM_(2.5~10.0)菌落数/浓度动态组高于静态组,无净化组高于净化组(均P0.05),真菌菌落数动态无净化组高于静态无净化组,静态净化组低于静态无净化组(均P0.05),动态净化组与无净化组间无明显差异(P=0.936)。结论人员活动增加支管镜室空气微生物和颗粒物的菌落数/浓度,空气净化器能降低支气管镜室空气中的细菌、总微生物和颗粒物的菌落数/浓度。     

2家甘蔗制糖企业蔗渣尘关键控制点与微生物污染状况调查

目的 调查广西2家甘蔗制糖企业蔗渣尘关键控制点与微生物污染状况.方法 针对A、B两家企业作业场所中的微生物采样采用自然沉降法进行检测.结果 甘蔗堆场、甘蔗落料口、打包机蔗渣尘关键控制点的粉尘浓度在0.96～8.89 mg/m3,甘蔗堆场、甘蔗落料口、打包机的菌落总数(均值)分别为240 cfu/m3(A)、357 cf...     

Mold and endotoxin levels in the aftermath of Hurricane Katrina: a pilot project of homes in New Orleans undergoing renovation

BACKGROUND: After Hurricane Katrina, many New Orleans homes remained flooded for weeks, promoting heavy microbial growth. OBJECTIVES: A small demonstration project was conducted November 2005-January 2006 aiming to recommend safe remediation techniques and safe levels of worker protection, and to characterize airborne mold and endotoxin throughout cleanup. METHODS: Three houses with floodwater lines between 0.3 and 2 m underwent intervention, including disposal of damaged furnishings and drywall, cleaning surfaces, drying remaining structure, and treatment with a biostatic agent. We measured indoor and outdoor bioaerosols before, during, and after intervention. Samples were analyzed for fungi [culture, spore analysis, polymerase chain reaction (PCR)] and endotoxin. In one house, realtime particle counts were also assessed, and respirator-efficiency testing was performed to establish workplace protection factors (WPF). RESULTS: At baseline, culturable mold ranged from 22,000 to 515,000 colony-forming units/m3, spore counts ranged from 82,000 to 630,000 spores/m3, and endotoxin ranged from 17 to 139 endotoxin units/m3. Culture, spore analysis, and PCR indicated that Penicillium, Aspergillus, and Paecilomyces predominated. After intervention, levels of mold and endotoxin were generally lower (sometimes, orders of magnitude). The average WPF against fungal spores for elastomeric respirators was higher than for the N95 respirators. CONCLUSIONS: During baseline and intervention, mold and endotoxin levels were similar to those found in agricultural environments. We strongly recommend that those entering, cleaning, and repairing flood-damaged homes wear respirators at least as protective as elastomeric respirators. Recommendations based on this demonstration will benefit those involved in the current cleanup activities and will inform efforts to respond to future disasters.     

Prospective survey of indoor fungal contamination in hospital during a period of building construction

An 18-month survey of indoor fungal contamination was conducted in one haematology unit during a period of construction work. Air was sampled with a portable Air System Impactor and surfaces with contact Sabouraud plates. During this survey the mean concentration of viable fungi in air was 4.2 cfu/m(3) and that for surfaces was 1.7 cfu/plate. At the beginning of construction work, there were increases in airborne fungal spores (from 3.0 to 9.8 cfu/m(3)) in the unit, but concentrations did not exceed 10 cfu/m(3) during the 18-month period. The most frequently recovered airborne fungi were Penicillium spp. (27-38%), Aspergillus spp. (25%) and Bjerkandera adusta, a basidiomycete identified with molecular tools (7-12%). Blastomycetes accounted for more than 50% of the fungal flora on surfaces. Investigating the impact of a new air-treatment system (mobile Plasmair units), there were significant reductions in fungal contamination for the Plasmer -treated rooms, and in these rooms we observed the same level of fungal load whether construction work was in progress or not.     

A 2‐year survey of the airborne mycoflora in a hospital environment

Studies on levels of airborne fungal spores in hospital wards and a diet kitchen were carried out for a period of 24 months using an air sampler. In a preliminary study using Sabouraud dextrose agar (SDA), SDA with chloramphenicol, acidified malt extract agar, oxytetracycline glucose yeast extract and Rose‐Bengal chloamphenicol varying levels of fungi were recovered on each of these media. Sabouraud medium, which is used to recover medically important fungi, showed relatively lower fungal counts with an average of 89 cfu m^‐3 as compared with counts > 210 cfu m^‐3 on all the other media. Fungi accounted for about 68% of the total viable counts and the predominant genera were Aspergillus, Fusarium, Monilia, Penicillium, Rhizopus, Monilia, Candida, Rhodotorula and Pichia. Spore counts were higher in the wards (303 cfu m^‐3) than in the diet kitchen (208 cfu m^‐3) The aerial fungal spore counts were 51% higher in all the areas sampled during the warmer months than the colder months but there was no major change in the types of fungi except that Chrysonilia species were only isolated between October and March when they accounted for < 5% of the total fungal isolates.     

某导弹坑道屯兵期间空气微生物分布规律调查

目的调查某部一条坑道在人员进驻状态下为期一个月的空气微生物分布规律,为制订针对性防护措施提供参考。方法利用固体培养基对洞口(对照1)、通风口(对照2)、住宿区A1、住宿区A2、工作区、就餐区、厕所7个点位分时段(9时、13时、19时、1时)进行29 d连续采样培养和检测。结果该坑道空气微生物总体分布90~1620 cfu/m~3,平均分布276~489 cfu/m~3,受人员活动、通风状况、内部构造等影响。洞口处空气微生物分布整体最低,平均172 cfu/m~3;通风口在通风状态下微生物分布整体最高,平均1181 cfu/m~3;人员活动区域中空气微生物分布规律:住宿区A1住宿区A2工作区厕所就餐区。结论坑道内空气微生物含量与人员进驻时间无明显关系,人员活动区域中空气微生物分布住宿区工作区厕所就餐区,但总体未超过室内空气标准要求。     

九江市空气微生物动态变化监测

目的 了解九江市空气微生物动态变化特征。方法于1998年7月(夏)和10月(秋)、1999年1月(冬)和4月(春)选择九江市有代表性的工业区、郊区、文化商业居住区、居民区、工业商业交通混合区、火车站地区进行空气微生物监测。结果 九江市不同功能分区空气微生物菌落数分别为工业商业交通混合区：1948cfu/m^3;工业区：1613cfu／m^3；文化商业居住区：1434cfu/m^3；居民区：1358cfu/m^3；火车站：1170cfu/m^3；郊区：552cfu/m^3。季节变化为夏季＞秋季＞春季＞冬季。每日不同时段的变化为11：00＞15：00＞23：00＞7：00＞19：00＞3：00。结论 九江市空气微生物菌落数的高峰出现在工业商业交通混合区的夏季，每日只出现1次高峰。