Mycotoxins in indoor environments

Exposure to mycotoxins produced by toxigenic molds growing in damp indoor spaces has been difficult to assess. Monitoring methods limit the characterization of inhalation exposure of any bioaerosol, especially that of mycotoxins. Biomarkers promise better ability to determine mycotoxin exposures 1.) through direct measures of toxins and their products in human tissues, 2.) through immunochemical methods, and 3.) measures of effect through novel approaches,e.g., proteomics or genomics. This paper summarizes both the problems inherent in measuring exposures and some of the promising methods that could help to resolve the current impasse. Presented at the 27^th Mykotoxin-Workshop, Dortmund, Germany, June 13–15, 2005.     

An indoor air model

Indoor aerobiological data sets are often difficult to handle because they are not easily related to climatic parameters similar to those found outdoors. However, in large buildings, where ventilation systems allow a systematic knowledge of air flows, the transfer of a power distribution model to airborne spore concentration can simplify the task of reaching a decision on contamination presence. The use of the absorption percentage of each component of the ventilation system (air intake, filters, cooling, humidification, air return) can identify abnormalities (i.e. concentrations not following the general expected model, which could mean contamination requiring action), permit direct cleaning, and allow the restoration of a normal state after a short period of time.     

Outdoor and indoor pollen grains in sofia

For frequently two years a period of the range and quantity of pollen grains in the most inhabited rooms of each of 4 dwellings in Sofia was studied, together with the outdoors air pollen spectra. Changes in the health status of the inhabitants affected by pollinosis were recorded at the same time. The characteristic pollen taxa, pollen interference periods and the way sensitive patients were affected were evaluated.     

Physiologic responses during indoor cycling

During the last decade, there has been active interest in indoor cycling (e.g., spinning) as a method of choreographed group exercise. Recent studies have suggested that exercise intensity during indoor cycling may be quite high and may transiently exceed Vo2max. This study sought to confirm these findings, as the apparent high intensity of indoor cycling has implications for both the efficacy and the risk of indoor cycling as an exercise method. Twenty healthy female students performed an incremental exercise test to define Vo2max and performed 2 videotaped indoor exercise classes lasting 45 minutes and 35 minutes. Vo2, heart rate (HR), and rating of perceived exertion (RPE) were measured during the indoor cycling classes, with Vo2 data integrated in 30-second intervals. The mean %Vo2max during the indoor cycling classes was modest (74 +/- 14% Vo2max and 66 +/- 14%Vo2max, respectively). However, 52% and 35% of the time during the 45- and 35-minute classes was spent at intensities greater than the ventilatory threshold (VT). The HR response indicated that 35% and 38% of the session time was above the HR associated with VT. In 10 of the 40 exercise sessions, there were segments in which the momentary Vo2 exceeded Vo2max observed during incremental testing, and the cumulative time with exercise intensity greater than Vo2max ranged from 0.5 to 14.0 minutes. It can be concluded that although the intensity of indoor cycling in healthy, physically active women is moderate, there are frequent observations of transient values of Vo2 exceeding Vo2max, and a substantial portion of the exercise bouts at intensities greater than VT. As such, the data suggest that indoor cycling must be considered a high-intensity exercise mode of exercise training, which has implications for both efficacy and risk.     

Mycotoxin production by indoor molds

Fungal growth in buildings starts at a water activity (a(w)) near 0.8, but significant quantities of mycotoxins are not produced unless a(w) reaches 0.95. Stachybotrys generates particularly high quantities of many chemically distinct metabolites in water-damaged buildings. These metabolites are carried by spores, and can be detected in air samples at high spore concentrations. Very little attention has been paid to major metabolites of Stachybotrys called spirocyclic drimanes, and the precise structures of the most abundant of these compounds are unknown. Species of Aspergillus and Penicillium prevalent in the indoor environment produce relatively low concentrations of mycotoxins, with the exception of sterigmatocystins that can represent up to 1% of the biomass of A. versicolor at a(w)'s close to 1. The worst-case scenario for homeowners is produced by consecutive episodes of water damage that promote fungal growth and mycotoxin synthesis, followed by drier conditions that facilitate the liberation of spores and hyphal fragments.     

Workload comparison between hiking and indoor physical activity

ABSTRACT: Fattorini, L, Pittiglio, G, Federico, B, Pallicca, A, Bernardi, M, and Rodio, A. Workload comparison between hiking and indoor physical activity. J Strength Cond Res 26(10): 2883-2889, 2012-Walking is a physical activity able to maintain and improve aerobic fitness. This activity can easily be performed in all seasons both outdoors and indoors, but when it is performed in its natural environment, the use of specific equipment is required. In particular, it has been demonstrated that the use of trekking boots (TBs) induces a larger workload than those used indoors. Because an adequate fitness level is needed to practice hiking in safety, it is useful to know the energy demand of such an activity. This research aims at defining the metabolic engagement of hiking on natural paths with specific equipment at several speeds and comparing this with indoor ones (on a treadmill). This can thence be used to define the load that better reflects the one required to walk on natural paths. The walking energy cost (joules per kilogram per meter) at several speeds (0.28, 0.56, 0.84, 1.11, and 1.39 m·s)-on level natural terrain while wearing suitable footwear (TBs) and on a treadmill at various raising slopes (0, 1, 2, 3, 4%) while wearing running shoes-was measured in 14 healthy young men (age 23.9 ± 2.9 years, stature 1.75 ± 0.04 m, and body mass 72.9 ± 6.3 kg). A physiological evaluation of all the subjects was performed before energy cost measurements. The results showed that outdoors, the oxygen uptake was consistently less than the ventilatory threshold at all speeds tested and that a 3% slope on the treadmill best reflects the outdoor walking energy expenditure. These findings will prove useful to plan proper training for hiking activity or mixed (outdoors and indoors) training program.     

Fungal pollution of indoor environments and its management

Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. Life style changes have resulted in a shift from open air environments to air tight, energy efficient, environments, in which people spend a substantial portion of their time. Most indoor air pollution comes from the hazardous non biological agents and biological agents. Fungi are ubiquitous in distribution and are a serious threat to public health in indoor environments. In this communication, we have reviewed the current status on biotic indoor air pollution, role of fungi as biological contaminants and their impact on human health.     

厦门地区室内植物的选择与配置

本文分析了室内绿化的作用,探讨了厦门地区室内植物选择和配置的方式,介绍了这一地区常见的可作为室内绿化的植物及其生态习性和用途。     

Biological responses to indoor air contaminants

Summary The scientific study of indoor air quality has been a topic for research in the last two decades; in the late 70's it became an issue of general public perception. The public perceptions have been such tremendous stimuli because they involve aspects of health and welfare (comfort and economics). Various biomedical studies were performed to evaluate adverse biological effects associated with ambient and occupational pollutants. However, it became obvious that humans were exposed more, on a temporal basis, to their normal indoor environments than they were either in the workplace or outside. Concern with biological contaminants was always an issue, but rarely examined indoors until recently. Biological responses to the indoor environment will be discussed in this paper.     

Mycotoxins as harmful indoor air contaminants

Fungal metabolites (mycotoxins) that pose a health hazard to humans and animals have long been known to be associated with mold-contaminated food and feed. In recent times, concerns have been raised about exposures to mycotoxin-producing fungi in indoor environments, e.g., damp homes and buildings. The principal mycotoxins that contaminate food and feed (alfatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone) are rarely if ever found in indoor environments, but their toxicological properties provide an insight into the difficulties of assessing the health effects of related mycotoxins produced by indoor molds. Although the Penicillium and Aspergillus genera of fungi are major contaminants of both food and feed products and damp buildings, the particular species and hence the array of mycotoxins are quite different in these environments. The mycotoxins of these indoor species and less common mycotoxins from Stachybotrys and Chaetomium fungi are discussed in terms of their health effects and the need for relevant biomarkers and long-term chronic exposure studies.     

Fungal fragments as indoor air biocontaminants

The aerosolization process of fungal propagules of three species (Aspergillus versicolor, Penicillium melinii, and Cladosporium cladosporioides) was studied by using a newly designed and constructed aerosolization chamber. We discovered that fungal fragments are aerosolized simultaneously with spores from contaminated agar and ceiling tile surfaces. Concentration measurements with an optical particle counter showed that the fragments are released in higher numbers (up to 320 times) than the spores. The release of fungal propagules varied depending on the fungal species, the air velocity above the contaminated surface, and the texture and vibration of the contaminated material. In contrast to spores, the release of fragments from smooth surfaces was not affected by air velocity, indicating a different release mechanism. Correlation analysis showed that the number of released fragments cannot be predicted on the basis of the number of spores. Enzyme-linked immunosorbent assays with monoclonal antibodies produced against Aspergillus and Penicillium fungal species showed that fragments and spores share common antigens, which not only confirmed the fungal origin of the fragments but also established their potential biological relevance. The considerable immunological reactivity, the high number, and the small particle size of the fungal fragments may contribute to human health effects that have been detected in buildings with mold problems but had no scientific explanation until now. This study suggests that future fungal spore investigations in buildings with mold problems should include the quantitation of fungal fragments.     

红萍室内养殖技术探讨

研究结果表明,光照是室内养殖红萍关键因子之一,最适光照为日光灯60001x+白炽灯60001x;其次是培养液;适当增加有机肥,尤其是动物的排泄物,能加速红萍的生长和繁殖速率;赤霉素的适当浓度(10~20mg/L)有利于提高红萍的生长速率。     

Toxic-metabolite-producing bacteria and fungus in an indoor environment.

Toxic-metabolite-emitting microbes were isolated from the indoor environment of a building where the occupant was suffering serious building-related ill-health symptoms. Toxic substances soluble in methanol and inhibitory to spermatozoa at <10 microg (dry weight) ml(-1) were found from six bacterial isolates and one fungus. The substances from isolates of Bacillus simplex and from isolates belonging to the actinobacterial genera Streptomyces and Nocardiopsis were mitochondriotoxic. These substances dissipated the mitochondrial membrane potential (Deltapsi) of boar spermatozoa. The substances from the Streptomyces isolates also swelled the mitochondria. The substances from isolates of Trichoderma harzianum Rifai and Bacillus pumilus damaged the cell membrane barrier function of sperm cells.     

Monitoring indoor pollen over two years

The present study monitored a private apartment for pollen that had settled on the floor. Pollen was sampled and analysed from two rooms over a period of two years. The study showed that pollen accumulations indoors are dominated by wind-pollinated species reflecting the current flowering season. The adjacent vegetation and the cleaning activities influenced the pollen content. Pollen from zoophilous plants mostly originated from ornamental plants within the flat. Similarities and differences between the two rooms and the two years were observed. These findings have implications for forensic investigations as well as allergological research.     

Media for cultivation of indoor streptomycetes

The growth of 10 indoor Streptomyces spp. isolates on nutritionally complex and selective 26 media revealed that the mycelium production had a tendency to increase in order: starch-casein < glycerol-arginine < glucose-tryptone, and NH(4)NO(3) < Na-caseinate-asparagine. Yeast extract increased mycelium biosynthesis, but not always the growth rate. The strains belonging to streptomycetes most common environmental isolates produced visible mycelium in 5 days on all media.     

适于室内绿化的棕榈科植物

本文就原产国内或引进的较有推广价值的适于室内绿化的棕桐科植物14个属作简要介绍。     

室内观赏植物对甲醛的吸收及抗逆效果研究

该研究采用密封舱法模拟室内甲醛污染环境(熏蒸箱内甲醛浓度设置为0.1~0.5 mg·m~(-3),熏气时间12 h),对6种常见室内观赏植物进行甲醛熏蒸实验,测定了植物对甲醛的吸收效率、叶面伤害指数及过氧化物酶(POD)等指标。结果表明:这6种常见观赏植物对甲醛均具较好的净化效果,甲醛熏蒸浓度为0.1~0.3 mg·m~(-3),白鹤芋对甲醛的净化效果最好;熏蒸浓度0.5 mg·m~(-3),绿萝和吊兰具有较好的净化和抗逆性能;铁线蕨对甲醛的耐受力较弱,适合作为室内甲醛污染的指示性植物。几种受试植物的POD酶与甲醛吸收率呈显著正相关关系(P0.05),表明植物POD活力变化是受甲醛胁迫后的主要抗逆应答机制之一。     

Assessment and modeling of indoor fungal and bacterial bioaerosol concentrations

In recent years, potentially harmfulmicroorganisms such as Stachybotryschartarum have garnered national attentionwhen implicated with indoor air problems. However, accurate assessment of biologicallycontaminated indoor air has proven to beprohibitively labor, time, cost, and trainingintensive. The model developed in this studyaccurately predicts the levels of biologicalindoor air contaminants for the GreaterCincinnati area using a number of independentvariables that can be quickly calculatedwithout expensive, time-consuming methods. Thirty-nine single-family residences in theGreater Cincinnati area were sampled usingAndersen two-stage viable microbial particlesizing sampler instruments loaded with MaltExtract Agar, Trypicase Soy Agar, Czapek'sCellulose Agar, and Corn Meal Agar. After airsampling, the Petri dishes were incubated, thenumber of colonies from each plate wereenumerated, and the total number of viablecolony forming units per cubic meter of airwere calculated. Independent variables (indoorrelative humidity, indoor temperature, outdoormold, season, water damage, visible mold,damaged materials, home age, remediationfactors, health questionnaire, number ofoccupants, and indoor pets) were then compared tothe dependent variable (fungal and bacterialbioaerosol counts) by multiple linearregression using Analyze-it^® for Microsoft Excel^®. The final air model predicted thetotal number of viable colony forming units percubic meter with 97% accuracy; the goal forthis model was 90% accuracy.     

Preliminary surveys of outdoor and indoor aeromycobiota in Uganda

This investigation was conducted during the period of March through June 1998 to trap, enumerate and identify the different airborne fungi in a variety of microhabitats of outdoor and indoor environments in different localities of Uganda. The settle plate method was used and Czapek-Dox agar was the isolation medium. A total of 47 genera and 61 species in addition to some other unidentified airborne fungi were trapped from all exposures at outdoor (39 genera and 52 species) and indoor (35 and 49) environments. The total fungal catches of outdoor airspora obtained from all exposures (and even in most individual exposures) were more than twice (5222 colonies) of that of the indoor ones (4361) when the exposure periods are taken into consideration. It is worth mentioning that the most highly polluted sites were either parks, forests or river banks for outdoor exposures, or teaching laboratory, library, laterines or bathrooms for indoor exposures. The most prevalent fungi from both outdoor and indoor microhabitats being species of Mycosphaerella, Yeasts, Penicillium, Fusarium, Aspergillus,Cochliobolus and Alternaria. However, several others were trapped frequently from either outdoor or indoor environments. On the other hand, several others were trapped only, but not frequently (in low or rare instances) from either outdoor or indoor microhabitats. The implications of these airborne spores are also discussed. This revised version was published online in June 2006 with corrections to the Cover Date.