Mold Testing Laboratory In Toronto
Mold & Bacteria Consulting Laboratories (MBL) is a leading provider of mold and bacteria testing services in the Greater Toronto Area (GTA) and the rest of Canada.
As a mold and bacteria laboratory, the lab specializes in the analysis of air and surface samples for:
- Bacteria including Coliforms, E.coli, Legionella testing, and total aerobic and anaerobic counts
- Mold analysis by culture methods: culturable air samples such as RCS, BioCassette, Andersen, SAS, etc.
- Mold analysis by direct microscopic examination: tape, bulk, swab, and water samples
- Total airborne fungal spore counts: Spore traps including Air-O-Cell, BioAire, and Micro5 cassettes, Allergenco, Burkard and BioSIS slides
MBL’s mold and bacteria testing services are not restricted to the Greater Toronto Area (GTA). We serve clients in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia and New Foundland.
MBL clients include:
- Industrial hygienists
- Environmental consultants
- Quality assurance managers
- Home Inspectors
- General contractors
- Cleaning and restoration contractors
- Property managers
- Insurance, financial, or legal professionals who deal with microbial contamination issues
For questions related to laboratory testing of samples, sampling methods, laboratory data interpretation and other issues related to microorganisms, please call 905-290-9101 (within Toronto area) or 1-866-813-0648 if calling outside the GTA.
MBL is Proficient For Bacteria Testing
The Canadian Association for Laboratory Accreditation Inc.(CALA) has rated MBL proficient for the following bacteria testing:
| Test Parameter | Method Of Analysis | Status |
| Escherichia coli (E. coli) | Membrane Filtration (DC-Agar) | Proficient |
| Fecal (Thermotolerant) Coliforms | Membrane Filtration (mFC) | Proficient. |
| Heterotrophic Plate Count (HPC) | Membrane Filtration (PCA) | Proficient |
| Total Coliforms | Membrane Filtration (DC-Agar) | Proficient. |
| Escherichia coli (E. coli) | Presence/Absence | Proficient |
| Total Coliforms | Presence/Absence | Proficient. |
Coliform Bacteria
The coliform bacteria are used as indicators of potential health risk for water. Coliforms are divided into 2 groups; total coliforms, i.e., all the coliform bacteria; and the fecal coliforms. The fecal coliforms are dominated by Escherichia coli (E. coli). E. coli are common in human intestines and they are generally harmless. However, some strains such as 0157 can cause serious infections.
Presence of fecal coliforms in water is widely accepted as indicator of potential contamination of water with fecal material. Contamination of water with fecal material presents greater risk of infectious microorganism such as viruses, other bacteria, protozoa and even worms.
Acceptable levels of total aerobic bacteria, yeast and mold in buildings
Question: What is the “normal / acceptable” level of total aerobic bacteria and yeast & mold in homes / buildings
Answer: There are no universally agreed acceptable levels of total aerobic bacteria, yeast and mold in buildings. However, you may find levels suggested by various organisations. I would say that since there will always be bacteria/mold/yeast in houses, any levels that appear abnormally high is uncceptable. However, apart from the levels, you have also to consider what organisms are present since some are more harmful or destructive than others.
The tables below show some levels published by the Commission of the European Communities in Indoor Air Quality & its Impact on Man: Report No. 12: Biological Particles in Indoor Environments. ECSC-EEC-EAEC, Brussels-Luxembourg, 1993.
Categories of CFU/m3 (mixed populations of fungi) obtained with the Andersen six-stage sampler in combination with MEA, and with the N6-Andersen one-stage sampler in combination with MEA and DG18.
| Category | Fungal Counts (CFU/m3) in Houses | Fungal Counts (CFU/m3) in non-industrial indoor environments |
|---|---|---|
| Very low | <50 | <25 |
| Low | <200 | <1,000 |
| Intermediate | <1,000 | <500 |
| High | <10,000 | <2,000 |
| Very High | >10,000 | >2,000 |
N.B.: These categories are based on the range of values obtained in indoor environments and not on a health risk evaluation.
Categories of CFU/g dust (mixed populations of fungi) obtained by direct
plating on V8 or DG18, and by suspension in peptone followed by plating on V8 or DG18, for houses and other non-industrial indoor environments
| Category | Method | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| V8/directa | DG18/directa | V8/peptoneb | DG18/peptoneb | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Very low | <1,000 | <2,000 | <10,000 | <10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Low | <2,500 | <6,000 | <20,000 | <20,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intermediate | <5,000 | <9,000 | <40,000 | <50,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| High | <10,000 | <15,000 | <100,000 | <120,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Very High | >10,000 | >15,000 | >100,000 | >120,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
a : direct plating of 30 mg dust
b: 100 mg dust suspended in a pepton solution (1 : 50), 0.1 ml of the solution plated on the medium
N.B. : These categories are based on the range of values obtained in indoor environments and not on a health risk evaluation.
Categories of CFU/m3 (mixed populations of bacteria) obtained with the
Andersen six-stage sampler or slit sampler (sampling time 10 – 15 min.,
incubation at 20 – 25°C for 3 – 5 days), for houses and non-industrial indoor environments.
| Category | Bacterial Counts (CFU/m3) in Houses | Bacterial Counts (CFU/m3) in non-industrial indoor environments |
|---|---|---|
| Very Low | <100 | <50 |
| Low | <500 | <100 |
| Intermediate | <2,500 | <500 |
| High | <10,000 | <2,000 |
| Very High | >10,000 | >2,000 |
N.B.: These categories are based on the range of values obtained in indoor environments and not on a health risk evaluation
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.
Testing For Sewage Contamination
Sewage contamination in building is the result of septic system backups or sewage pipe damages. Sewage backflow in a building can damage the integrity of its structure and render it inhabitable as well. Sewage contains a range of pathogenic microorganisms like E.coli, Salmonella, Vibrio, mycobacteria, moulds, viruses and protozoa like Cryptosporidium and Giardia. Recurrent sewage leaks or spills in particular areas such as the basement of residential or commercial buildings, allow all these micro-organisms to proliferate. Exposure to these pathogens poses a serious health risk.
What Should One Do After Sewage Back-up?
Once a building gets contaminated with sewage, the most important steps to be taken are immediate removal of sewage water, disinfection of the contaminated surfaces, and prompt drying of the surfaces. Sewage remediation may require special equipment such as heavy duty vacuum cleaners. Hiring the services of remediation or restoration professionals is therefore recommended.
Documentation of contaminated materials is important. It’s difficult to clean contaminated porous materials. Therefore, any material that is porous (such as carpet, gypsum wallboard, insulation, upholstered furniture, clothing) and directly got contaminated by sewage is supposed to be discarded since the pathogenic micro-organisms have already penetrated the material. Semi-porous material like wood furniture or pressed wood products may be thoroughly cleaned, disinfected and dried. Non-porous surfaces like metal, glass and ceramic tile floorings can be cleaned and disinfected.
Determining the effectiveness of sewage cleanup
Opinions differ as to whether microbial sampling to document effectiveness of sewage remediation is necessary. Those who think it’s not necessary argue that the primary objective of sewage remediation is to remove the sewage water and disinfecting and drying of contaminated interior surfaces. However those who support sampling recommend screening for E. coli and fecal coliforms. E. coli (Escherichia coli in full) are found in the intestines of humans and animals and hence in fecal matter which happens to be a major component of sewage. Direct or indirect contact with E. coli contaminated water, food, air or surfaces could lead to harmful health effects. E. coli is only used as an indicator since not all strains of E. coli are pathogenic. However, E. coli strain O157:H7 is a toxin producing strain and potentially dangerous.
Even though sewage may contain many other pathogens, E. coli is the easiest to detect and identify. Hence the reason it’s used as a marker of sewage contamination.
To ensure that sewage decontamination has been effectively done, a swab test is performed on surfaces. A suspect area is identified and marked. A swab is uniformly rolled over the entire marked area (e.g. 10cm x10cm) and enclosed back into its container. Such swabs are sent to the lab at the earliest for analytical purposes. The lab would then process the swabs for detection of E. coli and other coliforms. Along with determining the presence or absence of E. coli, it is highly recommended to quantify them. Quantification gives us an idea of the bacterial load of the particular suspect area. This helps also determine the effectiveness of the disinfecting agent.
If the lab results are positive for E. coli and other coliforms, further cleaning would be required.
How to collect bacteria samples
Various methods can be used to collect bacteria samples. The procedure will depend on what is being sampled and the type of data required. One may may be interested in a specific bacterium, in which case the method of sampling should be suitable for the recovery of that specific organism.
Sampling from surfaces
Sampling of bacteria from surfaces is usually performed using sterile swabs. Results from this test could be as simple as presence or absense of the bacterium of interest for example E. coli or Legionella. The test could also be detailed to include the amount of the bacterium present. It’s important to know how to collect samples for these different levels of analysis. If quantification is required, it’s important to swab a known surface area, for example 100 cm square. In this case the results would be expressed as “Number of colony forming units” per unit area.
Sampling bacteria samples from the air
To sample bacteria from the air, the air is impacted on some suitable growth media. The media to use will be determined by the type of bacteria being sampled for. If one is interested on a specific type of bacterium then a media that is selective for that bacterium should be used. To sample for the general population of bacteria in the air, then a media that can support the growth of many types of bacteria such as tryptic soy agar (TSA) should be used. Results are given as colony forming units per cubic meter of air.
Sampling for bacteria from water
Testing water for bacteria involves collecting a water sample in a sterile container and sending it to the lab for testing. The test results may just indicate the presence/absence of the bacterium of interest or may be detailed to include the amount present in terms of colony forming units per mililitre.