Aflatoxin B1: A review on metabolism, toxicity, occurrence in food, occupational exposure, and detoxification methods.

Damp buildings often have a moldy smell or obvious mold growth; some molds are human pathogens. This has caused concern regarding health effects of moldy indoor environments and has resulted in many studies of moisture- and mold-damaged buildings. Recently, there have been reports of severe illness as a result of indoor mold exposure, particularly due to Stachybotrys chartarum. While many authors describe a direct relationship between fungal contamination and illness, close examination of the literature reveals a confusing picture. Here, we review the evidence regarding indoor mold exposure and mycotoxicosis, with an emphasis on S. chartarum. We also examine possible end-organ effects, including pulmonary, immunologic, neurologic, and oncologic disorders. We discuss the Cleveland infant idiopathic pulmonary hemorrhage reports in detail, since they provided important impetus for concerns about Stachybotrys. Some valid concerns exist regarding the relationship between indoor mold exposure and human disease. Review of the literature reveals certain fungus-disease associations in humans, including ergotism (Claviceps species), alimentary toxic aleukia (Fusarium), and liver disease (Aspergillys). While many papers suggest a similar relationship between Stachybotrys and human disease, the studies nearly uniformly suffer from significant methodological flaws, making their findings inconclusive. As a result, we have not found well-substantiated supportive evidence of serious illness due to Stachybotrys exposure in the contemporary environment. To address issues of indoor mold-related illness, there is an urgent need for studies using objective markers of illness, relevant animal models, proper epidemiologic techniques, and examination of confounding factors.

http://dzumenvis.nic.in/microbes and plants growth/pdf/indoor mold, toxigenic fungi.pdf

Indoor Mold, Toxigenic Fungi, and Stachybotrys chartarum: Infectious Disease Perspective

Bioaerosols and occupational lung disease

Assessing the role of bioaerosols in residence-related symptoms involves (1) determining that symptoms are related to the residence by medical examination and careful questioning, (2) connecting reported symptoms with known or hypothesized effects of bioaerosols, (3) examining the residence for bioaerosol risk factors such as overcrowding/poor ventilation, inappropriate outdoor air intrusion, and dampness/standing water, (4) and finally, if no obvious risk factors are present, air sampling. Air sampling should always be a last resort and should use a reliable volumetric method. Particulate samplers, such as the Burkard personal spore trap, are inexpensive alternatives to viable particle samplers and will provide data on most organisms implicated in hypersensitivity diseases. Interpretation of residential bioaerosol sample data requires both qualitative and quantitative comparison with adjacent outdoor air and examination of aerosol changes related to domestic activities. Recommendations that should lead to a decrease in indoor bioaerosols include the use of air conditioning to allow limitation of outdoor aerosols, prevention of dampness or moisture intrusion, and discouraging the use of humidifying devices other than steam. Bioaerosol assessment in the workplace is often more complex than for residences. Because the symptomatic subjects are not in charge of the environment, such situations often lead to difficult employee/management relations and occasionally to litigation. It is essential that each step in workplace bioaerosol assessment be defensible and that the best possible methods are used. The approach is similar to the approach used for residences, but on a larger scale. Symptom assessment must include stress and ergonomic factors. Air sampling, if this is necessary, must usually be extensive with controls for ventilation rates, occupancy, and spatial variation.

https://www.jacionline.org/article/S0091-6749(05)80170-8/pdf

Bioaerosols: prevalence and health effects in the indoor environment.

ArticleBiological Action of Mycotoxins1

Samples of airborne dust generated during the handling' of aflatoxin-contaminated corn were collected and analyzed to assess potential exposures of farmers and other agricultural workers to these mycotoxins. Using high volume total dust samplers and a high volume Andersen sampler, downwind dust samples were collected on glass fiber filters when contaminated corn was transferred by augers from a storage bin into a wagon and back into the storage bin. The aflatoxin B1 content of the 15 dust samples ranged from 12.5 to 204.3 ppb, with an average of 138 ppb; the aflatoxin B2 content ranged from 1.1 to 41.6 ppb, with an average of 24.6 ppb. The B1 and B2 levels of contamination in the bulk corn were 223.9 and 17.5 ppb, respectively. The gravimetric dust concentration in the air ranged from 7 mg/m3 to 417 mg/m3. The samples taken with an Andersen sampler indicate the dust is relatively coarse with only approximately 17% less than 7 µm. An analysis of the dust from each stage showed higher levels of aflatoxins i...

Measurements of airborne aflatoxins during the handling of contaminated corn

of the combine, the average aflatoxin level was 2550 ng/g of dust. At one time, the operator was exposed to airborne dust containing 1360 ng/g while inside the combine cab. An airborne dust sample taken with a personal sampler during transfer of the corn to a truck had 52 000 ng/g. Airborne dusts collected while corn containing aflatoxin (1240­ 1850 ng/g) was being ground and fed had total aflatoxin levels ranging from nondetected to 43 700 ng/g. Airborne dust, bulk corn, and settled dust samples were collected at a grain elevator. Airborne dust samples collected during the delivery of corn in farm trucks to the elevator had an average of 1240 ng total aflatoxin/g. The airborne dust samples taken while corn was being unloaded from the elevator into trucks and railroad cars had lower average aflatoxin levels than those in dusts collected during delivery. Settled dusts in the elevator had 173-669 ng total aflatoxin/g. The highest aflatoxin level in the air in the elevator was 13 000 ng/cu. m near the conveyor belt. Airborne dust samples collected by personal samplers on elevator workers contained aflatoxin levels of 429-1300 ng/g; aflatoxin levels in the air were 9-1120 ng/cu.

Aflatoxin Levels in Airborne Dust Generated from Contaminated Corn During Harvest and at an Elevator in 1980

Determination of airborne 2,4-toluenediisocyanate vapors.

A new method for monitoring o-phenylenediamine (OPD) in the industrial environment was developed. Some aromatic amines such as OPD are difficult to collect and analyze directly because they are sensitive to oxidation. The method developed overcomes this difficulty by derivatizing the OPD directly upon collection. The OPD vapor is drawn through a bubbler containing acetic anhydride to form the relatively stable 1,2-diacetamidobenzene. The acetic anhydride solution is analyzed by means of high performance liquid chromatography (HPLC), and the diacetamido derivative quantified. The analysis is linear for standard solutions in the range of 0.5 µg/mL to over 0.5 mg/mL. Air concentrations of OPD were prepared by passing a metered stream of nitrogen through a glass tube packed with OPD crystals and diluting the stream with a metered air stream to achieve the desired level. The collection efficiency and conversion of OPD to the derivative was found to approach 100% at vapor concentrations of 0.09 mg/m3 but was re...

The development of an air sampling and analytic method for o-phenylenediamine in an industrial environment.

A method for collecting, storing and quantifying airborne vapors of O-phenylenediamine (OPD) in the workplace has been developed. The vapors are collected on 100 mg of Tenax-GC packed in 4 mm ID glass tubing wrapped with aluminum foil. The OPD is desorbed and derivatized using a 10% solution of acetic anhydride in acetonitrile to form diacetamidobenzene (DAAB). The DAAB was subsequently quantified by injecting 10 µL of the solution into a liquid chromatograph equipped with a UV-detector (254 nm), a Partisil PXS PAC column and a 7% methanol in 1-chlorobutane mobile phase. The limit of detection is approximately 10 ng. Samples collected from test atmospheres containing OPD in dry air at concentrations ranging from 0.05 to 0.2 mg/m3 gave an overall recovery of 86.6%. Recoveries of samples collected from atmospheres humidified to 80% relative humidity were 79%. The capacity of the tube is at least 25 µg which is sufficient for either short or long term samples.

William R. Burg

Papers

Measurements of airborne aflatoxins during the handling of contaminated corn

Aflatoxin Levels in Airborne Dust Generated from Contaminated Corn During Harvest and at an Elevator in 1980

Determination of airborne 2,4-toluenediisocyanate vapors.

The development of an air sampling and analytic method for o-phenylenediamine in an industrial environment.

A solid sorbent air sampling method for O-phenylenediamine (OPD)