Clinical medicine and the budding science of indoor mold exposure

Environmental factors influencing fungal growth on gypsum boards and their structural biodeterioration: A university campus case study

The new era in the design of modern healthy buildings necessitates multidisciplinary research efforts that link principles of engineering and material sciences with those of building biology, in order to better comprehend and apply underlying interactions among design criteria. As part of this effort, there have been an array of studies in relation to the effects of building characteristics on indoor microbiota and their propensity to cause health issues. Despite the abundance of scientific inquiries, limited studies have been dedicated to concomitantly link these effects to the deterioration of 'structural integrity' in the building materials. This study focuses on the observed biodeteriorative capabilities of indoor fungi upon the ubiquitous gypsum board material as a function of building age and room functionality within a university campus. We observed that the fungal growth significantly affected the physical (weight loss) and mechanical (tensile strength) properties of moisture-exposed gypsum board samples; in some cases, tensile strength and weight decreased by more than 80%. Such intertwined associations between the biodeterioration of building material properties due to viable indoor fungi, and as a function of building characteristics, would suggest a critical need towards multi-criteria design and optimization of next-generation healthy buildings. Next to structural integrity measures, with a better understanding of what factors and environmental conditions trigger fungal growth in built environment materials, we can also optimize the design of indoor living spaces, cleaning strategies, as well as emergency management measures during probable events such as flooding or water damage.

Effects of Mycotoxins on Neuropsychiatric Symptoms and Immune Processes

PURPOSE

The effects of air pollutants have been receiving increased attention both clinically and in the media. One such pollutant is mold, fungal growth in the form of multicellular filaments known as hyphae. The growth of molds is omnipresent not only in outdoor settings but also in indoor environments containing excessive amounts of moisture.

METHODS

PubMed was searched for relevant articles using terms such as mold, mycotoxins, fungi, immunity, inflammation, neurodevelopment, cognition, Alzheimer's, and autism.

FINDINGS

Exposure to molds is most commonly associated with allergies and asthma. However, it is now thought to be associated with many complex health problems, since some molds, especially Trichoderma, Fusarium and Stachybotrys spp, produce mycotoxins that are absorbed from the skin, airways, and intestinal lining. People exposed to molds and mycotoxins present with symptoms affecting multiple organs, including the lungs, musculoskeletal system, as well as the central and peripheral nervous systems. Furthermore, evidence has recently implicated exposure to mycotoxins in the pathogenesis of autism spectrum disorder. The effects of mycotoxins can be mediated via different pathways that include the secretion of pro-inflammatory cytokines, especially from mast cells.

IMPLICATIONS

The information reviewed indicates that exposure to mold and mycotoxins can affect the nervous system, directly or through immune cell activation, thus contributing to neurodevelopmental disorders such as autism spectrum disorder.

The Built Environment-A Missing "Cause of the Causes" of Non-Communicable Diseases

The United Nations "25 × 25 Strategy" of decreasing non-communicable diseases (NCDs), including cardiovascular diseases, diabetes, cancer and chronic respiratory diseases, by 25% by 2025 does not appear to take into account all causes of NCDs. Its focus is on a few diseases, which are often linked with life-style factors with "voluntary" "modifiable behavioral risk factors" causes tending towards an over-simplification of the issues. We propose to add some aspects of our built environment related to hazardous building materials, and detailed form of the construction of infrastructure and buildings, which we think are some of the missing causes of NCDs. Some of these could be termed "involuntary causes", as they relate to factors that are beyond the control of the general public.

What's out there making us sick?

Throughout the continuum of medical and scientific history, repeated evidence has confirmed that the main etiological determinants of disease are nutritional deficiency, toxicant exposures, genetic predisposition, infectious agents, and psychological dysfunction. Contemporary conventional medicine generally operates within a genetic predestination paradigm, attributing most chronic and degenerative illness to genomic factors, while incorporating pathogens and psychological disorder in specific situations. Toxicity and deficiency states often receive insufficient attention as common source causes of chronic disease in the developed world. Recent scientific evidence in health disciplines including molecular medicine, epigenetics, and environmental health sciences, however, reveal ineluctable evidence that deficiency and toxicity states feature prominently as common etiological determinants of contemporary ill-health. Incorporating evidence from historical and emerging science, it is evident that a reevaluation of conventional wisdom on the current construct of disease origins should be considered and that new knowledge should receive expeditious translation into clinical strategies for disease management and health promotion.

An analysis of almost any scientific problem leads automatically to a study of its history.

—Ernst Mayr

Cognitive function of 6-year old children exposed to mold-contaminated homes in early postnatal period. Prospective birth cohort study in Poland

In the last decade, the neurologic effects of various air pollutants have been the focus of increasing attention. The main purpose of this study was to assess the potential impact of early childhood exposure to indoor molds on the subsequent cognitive function of 6-year old children. The results of this study are based on the six-year follow-up of 277 babies born at term to mothers participating in a prospective cohort study in Krakow, Poland. The study participants are all non-smoking pregnant women who were free of chronic diseases such as diabetes and hypertension. The presence of visible mold patches on indoor walls was monitored at regular time intervals over gestation and after birth up to the age of five. The Wechsler Intelligence Scale for Children (WISC-R) was administered to children at age 6. The exposure effect of living in mold-contaminated homes on the IQ scores of children was adjusted for major confounders, known to be important for the cognitive development of children such as maternal education, the child's gender, breastfeeding practices in infancy, the presence of older siblings and the prenatal exposure to lead and environmental tobacco smoke (ETS). The adjusted IQ deficit attributed to longer exposures to indoor molds (>2 years) was significantly lower on the IQ scale (beta coeff.=-9.16, 95%CI: -15.21, -3.10) and tripled the risk of low IQ scoring (OR=3.53; 95%CI: 1.11-11.27) compared with references. While maternal education (beta coeff.=0.61, 95%CI: 0.05, 1.17) and breastfeeding (beta coeff.=4.0; 95%CI: 0.84, 7.17) showed a significant positive impact on cognitive function, prenatal ETS exposure (beta coeff.=-0.41; 95%CI: -0.79, -0.03) and the presence of older siblings (beta coefficient=-3.43; 95%CI: -5.67, -1.20) were associated with poorer cognitive function in children. In conclusion, the results of this study draw attention to the harmful effect of early postnatal exposure to indoor molds on children's cognitive development and provide additional evidence on the role of environmental determinants in human cognitive development.

The biocontaminants and complexity of damp indoor spaces: more than what meets the eyes

Nine types of biocontaminants in damp indoor environments from microbial growth are discussed: (1) indicator molds; (2) Gram negative and positive bacteria; (3) microbial particulates; (4) mycotoxins; (5) volatile organic compounds, both microbial (MVOCs) and non-microbial (VOCs); (6) proteins; (7) galactomannans; (8) 1-3-β-D-glucans (glucans) and (9) lipopolysaccharides (LPS — endotoxins). When mold species exceed those outdoors contamination is deduced. Gram negative bacterial endotoxins, LPS in indoor environments, synergize with mycotoxins. The gram positive Bacillus species, Actinomycetes (Streptomyces, Nocardia and Mycobacterium), produce exotoxins. The Actinomycetes are associated with hypersensitivity pneumonitis, lung and invasive infections. Mycobacterial mycobacterium infections not from M. tuberculosis are increasing in immunocompetent individuals. In animal models, LPS enhance the toxicity of roridin A, satratoxins G and aflatoxin B1 to damage the olfactory epithelium, tract and bulbs (roridin A, satratoxin G) and liver (aflatoxin B1). Aflatoxin B1 and probably trichothecenes are transported along the olfactory tract to the temporal lobe. Co-cultured Streptomyces californicus and Stachybotrys chartarum produce a cytotoxin similar to doxorubicin and actinomycin D (chemotherapeutic agents). Trichothecenes, aflatoxins, gliotoxin and other mycotoxins are found in dust, bulk samples, air and ventilation systems of infested buildings. Macrocyclic trichothecenes are present in airborne particles <2 μm. Trichothecenes and stachylysin are present in the sera of individuals exposed to S. chartarum in contaminated indoor environments. Haemolysins are produced by S. chartarum, Memnoniella echinata and several species of Aspergillus and Penicillium. Galactomannans, glucans and LPS are upper and lower respiratory tract irritants. Gliotoxin, an immunosuppressive mycotoxin, was identified in the lung secretions and sera of cancer patients with aspergillosis produced by A. fumigatus, A. terreus, A. niger and A. flavus.

Toxicant exposure and mental health--individual, social, and public health considerations

Thoughts and moods are the result of biological processes; disordered thoughts and moods may be the result of disordered biological processes. As brain dysfunction can manifest with emotional symptoms or behavioral signs, the etiology of some mental health afflictions and some abnormal conduct is pathophysiological rather than pathopsychological. Various studies confirm that some chemical toxicants which modify brain physiology have the potential to affect mood, cognitive function, and to provoke socially undesirable outcomes. With pervasive concern about myriad chemical agents in the environment and resultant toxicant bioaccumulation, human exposure assessment has become a clinically relevant area of medical investigation. Adverse exposure and toxicant body burden should routinely be explored as an etiological determinant in assorted health afflictions including disordered thinking, moods, and behavior. The impact of toxicant bioaccumulation in a patient with neuropsychiatric symptoms is presented for consideration as an example of the potential benefit of recognizing and implementing exposure assessment.

The environmental burden of disease in Canada: respiratory disease, cardiovascular disease, cancer, and congenital affliction

BACKGROUND

Exposure to environmental hazards contributes to many chronic diseases, yet the magnitude of their contribution to the total disease burden in Canada is not well understood.

OBJECTIVES

To estimate the environmental burden of disease (EBD) in Canada for respiratory disease, cardiovascular disease, cancer, and congenital affliction. Quantifying the contribution of environmental exposures to the overall burden of disease could play an important role in shaping public health and environmental policy priorities.

METHODS

The World Health Organization (WHO) recently estimated the environmental burden of disease globally by using a combination of comparative risk assessment data and expert judgment to develop environmentally attributable fractions (EAFs) of mortality and morbidity for 85 categories of disease. We use the EAFs developed by the WHO, EAFs developed by other researchers, and data from Canadian public health institutions to provide an initial estimate of the environmental burden of disease in Canada for four major categories of disease.

RESULTS

Our results indicate that: 10,000-25,000 deaths; 78,000-194,000 hospitalizations; 600,000-1.5 million days spent in hospital; 1.1 million-1.8 million restricted activity days for asthma sufferers; 8000-24,000 new cases of cancer; 500-2500 low birth weight babies; and between $3.6 billion and $9.1 billion in costs occur in Canada each year due to respiratory disease, cardiovascular illness, cancer, and congenital affliction associated with adverse environmental exposures.

CONCLUSIONS

The burden of illness in Canada resulting from adverse environmental exposures is significant. Stronger efforts to prevent adverse environmental exposures are warranted, including research, education, and regulation.