Investigation of fungal contamination in indoor environments normally includes visual inspection and sampling. The samples to collect, the number, when and where to collect them and the methods to be used for sample analyses depends on the objectives or goal of the investigation. The samples that may be collected include air, dust or bulk samples. Swabs or clear cellophane tape can be used to sample for fungi from contaminated surfaces. The samples can be analyzed by either direct microscopy or by culture methods depending on the type of data required.
Symptoms Of Mold Exposure
Mold exposure through inhalation of airborne spores may affect human health in many ways. Symptoms of mold exposure may vary from individual to individual. Some of the severe diseases associated with mold exposure include infection of the respiratory system (including the lungs) by species of Aspergillus. Aspergillus fumigatus, for example, is a common cause of Aspergillosis in individuals with weakened immune system.
A variety of other health problems have also been associated with airborne mold spores, such as chronic respiratory infections, dry cough, eye irritations, skin symptoms, asthmatic symptoms and allergy. Non-specific symptoms include headache, fever, and lack of concentration. Some of these symptoms of mold exposure can also be caused by other indoor contaminants.
Cladosporium herbarum
Cladosporium herbarum is a common outdoor and indoor mold. It is commonly found on dead herbaceous and woody plants, textiles, rubber, paper, and foodstuffs of all kinds.
In the indoor environment, Cladosporium herbarum is found in floor, carpet and mattress dust, damp acrylic painted walls, wallpaper, HVAC insulation, filters and fans. It is frequently the most prominent mold in air-spora. It grows over a wide range of temperatures, and has frequently been reported causing spoilage of meat in cold storage.
Cladosporium herbarum is not known to be toxigenic but can be highly allergenic to sensitive individuals. For more information about Cladosporium herbarum and other species of Cladosposporium, click http://www.moldbacteria.com/learnmore/cladosporium.html
Indoor Air Quality: Biological Pollutants
Indoor air quality is compromised by both biological and non-biological pollutants. Sources of biological pollutants include microorganisms, animal, insects and related organisms.
The most common biological pollutants of indoor air quality include molds and their byproducts, dust mites, pet dander (scales from hair, feathers, or skin), droppings and body parts from cockroaches, rodents and other pests or insects, viruses, and bacteria. Due to their small size, many of these biological pollutants are airborne and easily inhaled deep into the lungs.
Health Effects From Poor Indoor Air Quality
Some biological pollutants may cause serious health problems including hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma. Other health problems attributed to biological pollutants are sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems.
It is believed allergic reactions occur only after repeated exposure to a specific biological allergen. The reaction may occur immediately upon re-exposure or after multiple exposures over time. It’s important to regularly monitor the indoor air quality.
Testing For Airborne Mold Spore Concentration
Testing for airborne mold spore concentration is achieved by impacting a known volume of air onto a surface coated with sticky material. As the air hits the sticky surface the spores and any other particulates in the air are trapped. In the laboratory the spores are identified under a microscope, categorised into various groups and counted. This method is excellent for estimating how contaminated the air is but it does not tell us what proportion of the counted spores are still viable. If an estimate of the proportion of viable mold spores is needed, then the air has also to be impacted onto some growth agar media. Viable mold spores would then grow on the media and appear as mold colonies, usually referred to as colony forming units (CFU). CFU is not a very accurate way of measuring the viable proportion of airborne mold spores. This is because a single colony can develop from one spore or a group of spores. Secondly, fast growing colonies tend to overgrow slow growing colonies. Also, the agar media used may not support the growth of all categories of viable spores present in the air.
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