Penicillium aurantiogriseum
Penicillium aurantiogriseum is frequently isolated from feeds and food since it’s common in maturing crops, especially cereals. It is a producer of a number of mycotoxins. These include:
- Penicillic acid
- Roquefortine C
- Xanthomegnin
- Viomellein
- Verrucosidin
The health effects of these mycotoxins has not been reported.
The growth temperature for Penicillium aurentiogriseum ranges from 15-40 oC with an optimum temperature at 25 oC.
References
Pitt, J.l. (1988). “A Laboratory Guide to Common Penicillium Species”. 2nd ed. North Ryde, N.S.W.: CSIRO Division of Food Processing.
Black Mold Symptoms
When it comes to indoor mold, “Black Mold” is one of the most searched phrases on Google, Yahoo and MSN. According to the SEO Book Keyword Suggestion Tool, daily total search for “black mold” from Google, Yahoo and MSN is about 710 and if we include all phrases that contain the phrase “black mold”, the total daily search from the 3 search engines comes to about 1700.
But what is “Black Mold”? It refers to a mold known by the scientific name as Stachybotrys chartarum. It is not the only mold that appears black. Stachybotrys species thrive well on wet cellulose containing materials. Since it requires extremely wet conditions to grow, it’s one of the molds used as indicators of moisture damage.
The Controversy Regarding Black Mold symptoms
Scientists generally agree that exposure to damp, moldy home and workplace environments has serious health effects. However, clear causal relationship between individual or groups of mold and ill health is yet to be established. However, despite lack of proven evidence, the detection of Stachybotrys in the indoor environment has led to fear and panic and subsquent closure of office buildings and schools, and even burning of houses and household belongings in some situations.
Stachybotrys was first associated with a toxic response in horses in Eastern Europe and the Ukraine in the 1930s. Horses consuming contaminated straw or hay showed shock, dermal necrosis, leukopenia (a decrease in the white blood cell count), nervous disorders, and death. What fueled the fear for Stachybotrys was an outbreak, between 1993 and 1998, of idiopathic pulmonary hemorrhage (bleeding of lungs) in the Cleveland, Ohio, area where 37 infants were affected (see Infant Pulmonary Hemorrhage in a Suburban Home with Water Damage and Mold (Stachybotrys atra) ). An investigation led by the Centers for Disease Control and Prevention originally linked the outbreak to household exposure to Stachybotrys chartarum, and other molds (see Overview of Investigations into Pulmonary Hemorrhage among Infants in Cleveland, Ohio).
Most of the symptoms attributed to black mold still remain controversial since none of them has scientifically been proven. These symptoms include:
- Asthma and other respiratory problems
- chronic fatigue,
- Skin irritation
- lung bleeding
Bacteria As Contaminants In Indoor Environments
People spend around 80 and 90% of their time in indoor environments (office, school, home, etc) and there is increased awareness of the potential health effects of indoor biological contaminants. Therefore, when considering work or indoor living conditions, the air quality requires special attention.
In indoor environments, biological contaminants are often found in areas that provide conducive conditions for microbial growth. These include damp or wet areas such as cooling coils, humidifiers, condensate pans, draperies, bedding, carpet, and other areas where dust collects.
Bacteria are an important component of indoor biological contaminants. Some of them are pathogenic (that’s they are capable of causing disease) and are involved in respiratory diseases. If the environmental and nutritional conditions are favourable bacteria can colonize and grow on many surfaces (including standing water) from where they and their by-products can become airborne. A number of diverse activities can result in the dispersion and generation of bacterial aerosols indoors, for example, the operation of heating-ventilation-air conditioning systems, hot water systems and water spray devices.
Health Effects Associated With Indoor Bacteria
There are several health effects associated with exposures to bacterial aerosols. Some of them include irritative and nonspecific respiratory symptoms, respiratory infections, and allergic reactions such as alveolitis and chronic bronchitis.
Some of the infectious bacteria include Mycobacterium tuberculosis, Legionella pneumophila, Bacillus anthracis. These bacteria cause pulmonary tuberculosis, legionellosis (Legionnaire’s disease) and anthrax respectively. Infection is primarily through inhalation.
Bacteria As Causes Of Bioderioration
Bacteria are rarely thought of as biodeterioration agents. However, they are involved in biodeterioration of various types of materials. Bacillus sp, Nitrosomonas sp, Nocardia sp and Streptomyces are involved in biodeterioration of diverse materials in several regions. They cause physical damage and some are capable of producing acids that cause biochemical deterioration.
Conclusion
In general, several microorganisms including bacteria are present in indoor environments. They can contaminate indoor air and pose health risks especially when certain species are present or when they are in high numbers. Apart from the health effects microorganisms have the ability to cause damage to materials they are growing on.
Air Pollution and Childhood Respiratory Allergies
A study in the United States suggests that childhood respiratory allergies, which contribute to missed school days and other activity limitations, have increased in recent years, possibly due to environmental factors.
The study examined the associations between the reporting of respiratory allergy or hay fever and annual average exposure to particulate matter ? 2.5 µm in diameter (PM2.5), PM ? 10 µm in diameter, sulfur dioxide, and nitrogen dioxide and summer exposure to ozone.
Results showed that increased respiratory allergy/hay fever was associated with increased summer ozone levels and increased PM2.5.
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