Ventilation influence in occupational exposure to fungi and volatile organic compounds: poultry case

Introduction - In poultry houses, large-scale production has led to increased bird densities within buildings. Such high densities of animals kept within confined spaces are a source of human health problems related to occupational organic dust exposure. This organic dust is composed of both non-viable particles and viable particulate matter (also called bioaerosols). Bioaerosols are comprised by airborne bacteria, fungi, viruses and their by-products, endotoxins and mycotoxins. Exposure to fungi in broiler houses may vary depending upon the applied ventilation system. Ventilation can be an important resource in order to reduce air contamination in these type of settings. Nevertheless, some concerns regarding costs, sensitivity of the animal species to temperature differences, and also the type of building used define which type of ventilation is used. Aim of the study - A descriptive study was developed in one poultry unit aiming to assess occupational fungal and volatile organic compounds (VOCs) exposure.

Comparison of indoor and outdoor fungi and particles in poultry units

A descriptive study was developed in order to compare indoor and outdoor air contamination caused by fungi and particles in seven poultry units. Twenty eight air samples of 25 litters were collected through the impaction method on malt extract agar. Air sampling and particles concentration measurement were done in the interior and also outside premises of the poultries’ pavilions. Regarding the fungal load in the air, indoor concentration of mold was higher than outside air in six poultry units. Twenty eight species / genera of fungi were identified indoor, being Scopulariopsis brevicaulis (40.5%) the most commonly isolated species and Rhizopus sp. (30.0%) the most commonly isolated genus. Concerning outdoor, eighteen species/genera of fungi were isolated, being Scopulariopsis brevicaulis (62.6%) also the most isolated. All the poultry farms analyzed presented indoor fungi different from the ones identified outdoors. Regarding particles’ contamination, PM2.5, PM5.0 and PM10 had a statistically significant difference (Mann-Whitney U test) between the inside and outside of the pavilions, with the inside more contaminated (p=.006; p=.005; p=.005, respectively). The analyzed poultry units are potential reservoirs of substantial amounts of fungi and particles and could therefore free them in the atmospheric air. The developed study showed that indoor air was more contaminated than outdoors, and this can result in emission of potentially pathogenic fungi and particles via aerosols from poultry units to the environment, which may post a considerable risk to public health and contribute to environmental pollution.

Horse stable environment: what to expect regarding fungi and particles occupational exposure?

The simultaneous presence of fungi and particles in horse stable environment can create a singular exposure condition because particles have been reported has a good carrier for microorganisms and their metabolites. This study intends to characterize this setting and to recognize fungi and particles occupational exposure.

Environmental mycology in public health: fungi and mycotoxins risk assessment and management

Fungi are essential to the survival of our global ecology, but they might pose a significant threat to the health of occupants when they grow in our buildings. The exposure to fungi in homes is a significant risk factor for a number of respiratory symptoms. Well-known illnesses caused by fungi include allergy and hypersensitivity pneumonitis. Environmental monitoring for fungi and their disease agents are important aspects of exposure assessment, but few guidelines exist for interpreting their health impacts. This book answers the questions: How does one detect and measure the presence of indoor fungi? What is an acceptable level of indoor fungi? How do we relate this information to human health problems?

Occupational exposure to fungi and particles in animal feed industry

Background: Very few studies regarding fungal and particulate matter (PM) exposure in feed industry have been reported, although such contaminants are likely to be a significant contributing factor to several symptoms reported among workers. The purpose of this study has been to characterize fungal and dust exposure in one Portuguese feed industry. Material and Methods: Air and surface samples were collected and subject to further macro- and microscopic observations. In addition we collected other air samples in order to perform real-time quantitative polymerase chain reaction (PCR) amplification of genes from Aspergillus fumigatus and Aspergillus flavus complexes as well as Stachybotrys chartarum. Additionally, two exposure metrics were considered – particle mass concentration (PMC), measured in 5 different sizes (PM0.5, PM1, PM2.5, PM5, PM10), and particle number concentration (PNC) based on results given in 6 different sizes in terms of diameter (0.3 μm, 0.5 μm, 1 μm, 2.5 μm, 5 μm and 10 μm). Results: Species from the Aspergillus fumigatus complex were the most abundant in air (46.6%) and in surfaces, Penicillium genus was the most frequently found (32%). The only DNA was detected from A. fumigatus complex. The most prevalent in dust samples were smaller particles which may reach deep into the respiratory system and trigger not only local effects but also the systemic ones. Conclusions: Future research work must be developed aiming at assessing the real health effects of these co-exposures.

Climate changes influence in occupational exposure to fungi and mycotoxins

Climate changes and their effects on fungal distribution and activity are aspects of concern regarding the human exposure to mycotoxins. An exhaustive search was made for papers available in scientific databases reposrting the influence that climate cchange has on fungi and mycotoxins. Also a review regarding fungal burden, collected between 2010 and 2015 in different settings, was done to support the discussion about future fungi and mycotoxins ocuupational exposure. A. flavus complex, E. graminerarum complex and F. verticilliodes were the most reported to be influenced by climate changes. We noted also that the analyzed Portuguese settings presented already an occupational problem due to their fungal burden. It will be important to know future climate changes to select what complexes/species and strains, and consequently the mycotoxins, we should consider as indicators of an occupational problem. In addition, epidemiologic studies are needed to increase knowledge about potential health effects related with the exposure to both risk factors.

Horse stable environment: what to expect regarding fungi and particles occupational exposure?

The simultaneous presence of fungi and particles in horse stable environment can create a singular exposure condition because particles have been reported has a good carrier for microorganisms and their metabolites. This study intends to characterize this setting and to recognize fungi and particles occupational exposure.

Fungi, bacteria and pollens seasonally quantified at 3 basic schools in Lisbon: evaluation of ventilation need

Nowadays, most individuals spend about 80% of their time indoor and, consequently, the exposure to the indoor environment becomes more relevant than to the outdoor one. Children spend most of their time at home and at school and evaluations of their indoor environment are important for the time-weighted exposure. Due to their airways still in development, children are a sensitive group with higher risk than adults. Larger impact in health and educational performance of children demand indoor air quality studies of schools. The aim of this study was to assess the children exposure to bioaerosols. A methodology based upon passive sampling was applied to evaluate fungi, bacteria and pollens; its procedures and applicability was optimized. An indoor air study by passive sampling represents an easier and cheaper method when comparing with the use of automatic active samplers. Furthermore, it is possible to achieve important quality information without interfering in the classroom activities. The study was conducted in three schools, representative of different environments in the Lisbon urban area, at three different periods of the year to obtain a seasonal variation, to estimate the variability through the city and to understand the underneath causes. Fungi and bacteria were collected indoor and outdoor of the classrooms to determine the indoor/outdoor ratios and to assess the level of outdoor contamination upon the indoor environment. The children's exposure to pollen grains inside the classrooms was also assessed.

Fungi, MVOCs and dust exposure assessment in poultry production

Agricultural workers especially poultry farmers, are at increased risk of occupational respiratory diseases. In poultry production besides fungi microbial volatile organic compounds (MVOCs) are also present due to compounds released during fungal metabolism. Dust is also one of the risk factors present in animal housing and is comprised by poultry residues, fungi and feathers. A study was developed aiming to assess occupational exposure to fungi, MVOCs and dust in seven poultry units located in Portugal.

Exposure to particles and fungi in Portuguese swine production

Versão preprint.

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonateand 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)-(PPh3)] (2), [Ag(Tpms)(PCy3)] (3), [Ag(PTA)][BF4] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh3 = triphenylphosphane, PCy3 = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane) have been synthesized and fully characterized by elemental analyses, H-1, C-13, and P-31 NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N-3-facially coordinating mode, while in 2 and 5 a N2O-coordination is found, with the SO3 group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains Enterococcus faecalis (ATCC 29922), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Streptococcus pyogenes (SF37), Streptococcus sanguinis (SK36), Streptococcus mutans (UA1S9), Escherichia coli (ATCC 25922), and the fungus Candida albicans (ATCC 24443). Complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA EB system on addition of Ag complexes shows that the fluorescence quenching of DNA EB complex occurs and compound 3 is particularly active. Complexes 1-5 exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO3, which has been used as a control, following the same order of activity inhibition on DNA, i.e., 3 > 2 > 1 > 5 > AgNO3 >> 4.

Fungal contamination: comparation between Portuguese poultries and swines

Animal confinement tends to increase the overall microbial load in the production environment caused by high amounts of feed and organic residuals (manure and wastewater) present in those environments. The number of animais and the handling and management required to work in these settings also contribute to enhance that microbial ioad. Animal housing typically exposes workers to substantial concentrations of bioaerosols, such as fungi and their metabolites. Therefore, agricultural workers, and especially pig and poultry farmers, are at increased risk of occupational respiratory diseases. Exposure to bioaerosols in poultries and swines may vary depending upon the stage of the animals' growth, density, manure management procedures, litter type and used floor coverage, among others. Gathering temporal information about the quantity and the composition of fungal load is necessary to better understand the relationship between these factors and adverse health symptoms of workers. This study aimed to characterize and compare fungal contamination between these two different settings.

Occupational exposure to toxigenic fungi from Aspergillus flavus complex

Bioaerosols are mainly composed of fungal particles, bacteria and plant spores, being fungi responsible for the release of VOCs and micotoxins into indoor environments. Aspergillus flavus is a common opportunistic pathogen causing human infections and is involved in the production of aflatoxin and other secondary metabolites associated with toxic and allergic reactions. Poultry workers are exposed to high concentrations of fungi and are therefore more prone to develop associated pathologies. To evaluate occupational exposure of the workers to Aspergillus flavus and aflatoxins, six animal production facilities were selected, including 10 buildings, from which indoor air samples and outdoor reference samples were obtained. Twenty-five duplicate samples were collected by two methodologies: impactation onto malt extract agar of 25L air samples using a Millipore Air Tester were used to evaluate quantitative (CFU/m3) and qualitative (species identification, whenever possible) sample composition; 300 L air samples collected with the Coriolis Air Sampler into phosphate–saline buffer were used to isolate DNA, following molecular identification of Aspergillus section flavi using nor-1 specific primers by real-time PCR.

Mould and yeast identification in archival settings: preliminary results on the use of traditional methods and molecular biology options in Portuguese archives

This project was developed to fully assess the indoor air quality in archives and libraries from a fungal flora point of view. It uses classical methodologies such as traditional culture media – for the viable fungi – and modern molecular biology protocols, especially relevant to assess the non-viable fraction of the biological contaminants. Denaturing high-performance liquid chromatography (DHPLC) has emerged as an alternative to denaturing gradient gel electrophoresis (DGGE) and has already been applied to the study of a few bacterial communities. We propose the application of DHPLC to the study of fungal colonization on paper-based archive materials. This technology allows for the identification of each component of a mixture of fungi based on their genetic variation. In a highly complex mixture of microbial DNA this method can be used simply to study the population dynamics, and it also allows for sample fraction collection, which can, in many cases, be immediately sequenced, circumventing the need for cloning. Some examples of the methodological application are shown. Also applied is fragment length analysis for the study of mixed Candida samples. Both of these methods can later be applied in various fields, such as clinical and sand sample analysis. So far, the environmental analyses have been extremely useful to determine potentially pathogenic/toxinogenic fungi such as Stachybotrys sp., Aspergillus niger, Aspergillus fumigatus, and Fusarium sp. This work will hopefully lead to more accurate evaluation of environmental conditions for both human health and the preservation of documents.

Assessment of fungal contamination in waste sorting and incineration: case study in Portugal

Organic waste is a rich substrate for microbial growth, and because of that, workers from waste industry are at higher risk of exposure to bioaerosols. This study aimed to assess fungal contamination in two plants handling solid waste management. Air samples from the two plants were collected through an impaction method. Surface samples were also collected by swabbing surfaces of the same indoor sites. All collected samples were incubated at 27◦C for 5 to 7 d. After lab processing and incubation of collected samples, quantitative and qualitative results were obtained with identification of the isolated fungal species. Air samples were also subjected to molecular methods by real-time polymerase chain reaction (RT PCR) using an impinger method to measure DNA of Aspergillus flavus complex and Stachybotrys chartarum. Assessment of particulate matter (PM) was also conducted with portable direct-reading equipment. Particles concentration measurement was performed at five different sizes (PM0.5; PM1; PM2.5; PM5; PM10). With respect to the waste sorting plant, three species more frequently isolated in air and surfaces were A. niger (73.9%; 66.1%), A. fumigatus (16%; 13.8%), and A. flavus (8.7%; 14.2%). In the incineration plant, the most prevalent species detected in air samples were Penicillium sp. (62.9%), A. fumigatus (18%), and A. flavus (6%), while the most frequently isolated in surface samples were Penicillium sp. (57.5%), A. fumigatus (22.3%) and A. niger (12.8%). Stachybotrys chartarum and other toxinogenic strains from A. flavus complex were not detected. The most common PM sizes obtained were the PM10 and PM5 (inhalable fraction). Since waste is the main internal fungal source in the analyzed settings, preventive and protective measures need to be maintained to avoid worker exposure to fungi and their metabolites.