Mold populations and dust mite allergen concentrations in house dust samples from across Puerto Rico

The development and application of the Environmental Relative Moldiness Index (ERMI)

The prevalence of asthma in the United States (U.S.) has doubled since 1970, coinciding with the increased use of gypsum-drywall in home construction. Mold growth is promoted when gypsum-drywall gets wet. Since asthma is linked to mold exposures, accurate quantification of mold contamination in homes is critical. Therefore, qPCR assays were created and then used to quantify 36 common molds in dust collected in representative U.S. homes during the first American Health Homes Survey (AHHS). The concentrations of the 36 molds, i.e. 26 water-damage molds (Group 1) and 10 outside molds (Group 2), were used in the formulation of a home's Environmental Relative Moldiness Index (ERMI) value. The ERMI values for each of the AHHS homes were assembled from lowest to highest to create the ERMI scale, which ranges from -10 to 20. Subsequent epidemiological studies consistently demonstrated that higher ERMI values were linked to asthma development, reduced lung capacity or occupant asthma. Reducing mold exposures by remediation or with HEPA filtration resulted in a reduced prevalence of asthma and improvements in respiratory health. The ERMI scale has also been successfully applied in evaluating mold concentrations in schools and large buildings and appears to have applications outside the U.S.

Detection and assessment of dust mite allergens in an indoor environment in Anhui, China

Dust in the home environment is thought to be a potential trigger for increasing allergic diseases, such as allergic rash, rhinitis, asthma, and other conditions, associated with dust mites. To verify the status of dust mite prevalence in indoor surroundings, we collected 189 dust samples from the air conditioner filters (n = 75) and floors (n = 114) of households, schools, and hotels in the Anhui area, China. All samples were measured for dust mite breeding rate and breeding density under light microscopy and analyzed for dust mite species Dermatophagoides farinae 1 (Der f 1) and Dermatophagoides pteronyssinus 1 (Der p 1) allergen using enzyme-linked immunosorbent assay (ELISA). The dust mite breeding rates were 34.67% (26/75) and 20.18% (23/114), respectively, in the dust samples from the floor and air conditioning filters. The breeding density was the highest in households (10/g), followed by schools (9/g) and hotels (4/g). ELISA indicated that the allergen threshold (2.0 µg/g dust) of Der f 1 was exceeded in only two samples and Der p 1 in one sample. Additionally, a questionnaire was used to investigate the health knowledge on allergic diseases involved in indoor facilities, finding that most allergy sufferers were aware that indoor dust might be responsible for their conditions. The findings suggest that regular maintenance of indoor hygiene and cleaning of air-conditioning filters should reduce the risks of exposure to indoor allergens.

Health outcomes in redlined versus non-redlined neighborhoods: A systematic review and meta-analysis

BACKGROUND

Redlining was a racialized zoning practice in the U.S. that blocked fair access to home loans during the 1930s, and recent research is illuminating health problems in the current residents of these historically redlined areas. However, this work has not yet been holistically summarized. Here, we present the first systematic review and meta-analysis comparing health outcomes in redlined versus non-redlined neighborhoods in U.S. cities.

METHODS

We extracted relevant articles in PubMed, Web of Science, Cochrane and Science Direct databases published from January 2010 to September 2021.

RESULTS

The search revealed 12 studies on preterm births (n = 3), gunshot-related injuries (n = 2), cancer (n = 1), asthma (n = 1), self-rated health (n = 1), multiple health outcomes (n = 2), heat-related outcomes (n = 1) and COVID-19 incidence and mortality (n = 1). A meta-analysis of three studies found the odds of having preterm birth was significantly higher (OR = 1.41, 95% CI: 1.05, 1.88; p = 0.02) among women living in redlined areas compared to those in non-redlined areas. Review of other outcomes revealed that gunshot-related injuries, asthma, heat-related outcomes, and multiple chronic conditions were worse in redlined areas, while associations with cancer varied by cancer type. In terms of cause-specific mortality, one study revealed no link between residential redlining and infant mortality rate, while one study on COVID-19 outcomes was inconclusive.

CONCLUSIONS

Overall, this review presents evidence that living in historically redlined areas is associated with increased risk of multiple serious adverse health outcomes. Further research on mechanisms, remediation, and neighborhood-level interventions is needed to strengthen the understanding of the impacts of redlining on health.

Indoor Microbial Exposures and Chronic Lung Disease: From Microbial Toxins to the Microbiome

Effects of environmental microbial exposures on human health have long been of interest. Microbes were historically assumed to be harmful, but data have suggested that microbial exposures can modulate the immune system. We focus on the effects of indoor environmental microbial exposure on chronic lung diseases. We found contradictory data in bacterial studies using endotoxin as a surrogate for bacterial exposure. Contradictory data also exist in studies of fungal exposure. Many factors may modulate the effect of environmental microbial exposures on lung health, including coexposures. Future studies need to clarify which method of assessing environmental microbial exposures is most relevant.

Comparison of Atmospheric Fungal Spore Concentrations between Two Main Cities in the Caribbean Basin

OBJECTIVE

Fungal spores are ubiquitous in the atmosphere worldwide, but their distribution is not homogeneous at different locations. Most studies have compared airborne fungal spores ecology in temperate zones, but less is known about the tropics.

METHODS

This study compared, through statistical analysis of archived datasets, the predominant fungal groups, patterns and meteorological variables affecting airborne fungal spore concentrations between two major cities in the Caribbean (Havana and San Juan) during the year 2015.

RESULTS

In Havana, the predominant fungal group was Cladosporium while in San Juan were basidiospores. Our data provide evidence of differences and similarities in the monthly distribution of airborne spores in Havana and San Juan, but Cladosporium, ascospores y basidiospores had comparable hourly patterns in both cities and were affected by the same meteorological variables.

CONCLUSION

Our study provides additional evidence to help design allergy interventions.

Application of the Environmental Relative Moldiness Index in Indoor Marijuana Grow Operations

OBJECTIVES

Indoor marijuana grow operations (IMGOs) are increasing due to legalization of recreational and medicinal cannabis at the state level. However, the potential exposures of IMGO workers have not been well studied. Mold exposure has been identified as a major occupational health concern. Mold-specific quantitative polymerase chain reaction (MSQPCR) can provide quantitative exposure data for fungi at the species level. The purpose of this study was to characterize the airborne fungal burden using MSQPCR and to evaluate the applicability of an airborne Environmental Relative Moldiness Index (ERMI) in IMGOs.

METHODS

Air and dust samples were collected inside and outside the IMGOs and then analyzed via MSQPCR. These data were then used to calculate IMGO-specific ERMI scores. Culturable air samples were collected on agar plates and analyzed via microscopy. Differences were evaluated between indoor and outdoor concentrations, as well as between air and dust samples. The agreement between MSQPCR and culture-based methods was also evaluated.

RESULTS

Based on the geometric means for non-zero values of each fungal species across all IMGOs, the total airborne concentration was approximately 9100 spore equivalent (SE) m-3 with an interquartile range (IQR) of 222 SE m-3. The indoor/outdoor ratio of geometric means across all 36 species per IMGO ranged from 0.4 to 6.2. Significantly higher indoor concentrations of fungal species, including Aspergillus spp., were observed. An average airborne ERMI score of 7 (IQR = 7.6) indicated a relatively high burden of mold across a majority of operations. The ERMI scores were driven by the high concentrations of Group 1 species with a mean of 15.8 and an IQR of 13. There were 63 additional species identified in the culturable air samples not included in the ERMI.

CONCLUSIONS

High concentrations of airborne fungi were identified in IMGOs. Our evaluation of the ERMI based on MSQPCR as a rapid diagnostic and risk assessment tool for industrial hygienists in the IMGO setting is equivocal. ERMI did not identify all relevant fungal species associated with this specific occupational environment. We identified several issues with using the ERMI calculation. At this time, the catalog of fungal species needs to optimized for the occupational setting to ensure adequate coverage, especially for those species expected to be found in this burgeoning industry. Further research is necessary to elucidate the link between the ERMI score of airborne samples, worker exposure and health effects in grows to generate an acceptable index score for use in occupational exposure assessments.

Weathering the pandemic: How the Caribbean Basin can use viral and environmental patterns to predict, prepare, and respond to COVID-19

The 2020 coronavirus pandemic is developing at different paces throughout the world. Some areas, like the Caribbean Basin, have yet to see the virus strike at full force. When it does, there is reasonable evidence to suggest the consequent COVID‐19 outbreaks will overwhelm healthcare systems and economies. This is particularly concerning in the Caribbean as pandemics can have disproportionately higher mortality impacts on lower and middle‐income countries. Preliminary observations from our team and others suggest that temperature and climatological factors could influence the spread of this novel coronavirus, making spatiotemporal predictions of its infectiousness possible. This review studies geographic and time‐based distribution of known respiratory viruses in the Caribbean Basin in an attempt to foresee how the pandemic will develop in this region. This review is meant to aid in planning short‐ and long‐term interventions to manage outbreaks at the international, national, and subnational levels in the region.

Inter‐tropical regions have seen a slower spread of SARS‐CoV‐2 compared to temperate ones, suggesting viral spreading could likely be influenced by environmental factors.

Other coronaviruses also seem to respond to environmental factors, with peaks closely following the geotemporal patterns of influenza.

In the Caribbean, timing interventions to fight COVID‐19 around the projected peaks of influenza is a reasonable public health approach.

Risk factors for wheezing in primary health care settings in the tropics

BACKGROUND

The International Study of Wheezing in Infants (EISL) is a cross-sectional, population-based study, based on ISAAC (http://www.isaac.auckland.ac.nz). It uses a validated questionnaire on early wheezing and risk/protective factors.

OBJECTIVE

To apply the EISL questionnaire regarding wheezing events in 0- to 12-month-old infants with or without atopic background searching for risk factors in the tropics.

METHODS

The population was toddlers coming in for a checkup or 12-months' vaccination in primary health care clinics of a tropical city. Apart from child factors (eg, daycare attendance), we evaluated home factors (eg, air conditioning, bathroom, carpet, >6 persons, pollution) and mothers' factors (eg, education level, employment, cellphone). Data analysis was descriptive and case-control, with as cases atopic (AW) or non-atopic (NAW) wheezing children vs healthy controls. Wheezing-associated factors were evaluated using multivariate analysis, adjusted for the relation of AW/NAW with factors that were significant in prior univariate analysis.

RESULTS

The study included 999 toddlers. Any wheeze: 31.3%, recurrent wheeze (≥3 episodes): 12.1%. Major risk factors for AW (OR; 95%CI) included smoking (11.39; 2.36-54.99), common cold before 3 months of life (3.72; 2.59-5.36), mold (3.48; 2.28-5.30), kitchen indoors (2.40; 1.27-4.54), and pets (1.69; 1.09-2.62); breastfeeding was almost protective. For NAW, common cold and pets were risk factors, but cesarean section (0.44; 0.23-0.82), more than 1 sibling (0.33; 0.18-0.61), and breastfeeding for longer than 3 months (0.50; 0.28-0.91) were protective.

CONCLUSION

Wheezing is a health care burden. We found potential new risk factors for AW, some possibly unique for tropical climates. We suggest testing several hypotheses: could early AW be reduced in the tropics by attacking mold growth? Enhancing cooking place ventilation? Keeping pets outside? Or by postponing daycare attendance until after 4 months of age and avoiding (passive) smoking during pregnancy?

Generation and purification of monoclonal antibodies against Der f 2, a major allergen from Dermatophagoides farinae

Monoclonal antibodies (mAbs) are needed for the quantitation of environmental allergens for precise diagnosis and immunotherapy. In this study, we produced and purified monoclonal antibodies against Der f 2, one of the major allergens of the house dust mite Dermatophagoides farina, in order to develop an assay for the detection of this allergen. BALB/c mice were immunized four times with the protein Der f 2 together with an adjuvant after which splenocytes were collected and fused with SP2/0 (myeloma cells) in the presence of polyethylene glycol (PEG). The fused cells were selected in the presence of Hypoxanthine-Aminopterin-Thymidine (HAT) and then Hypoxanthine-Thymidine (HT) medium. Positive cells were screened with ELISA and subcloned by limited dilution at least three times to achieve stable mAb-producing clones. Four stable mAb-producing clones were obtained. One clone with IgG1 isotype and another with IgG2b isotype were chosen to produce large amounts of mAb by inoculation of the cells into the abdominal cavity of mice. Ascites were collected and the mAbs were purified using protein A affinity chromatography. Testing of the ascites by ELISA showed the titration of IgG1 and IgG2b to be higher than 1/10(6) dilution. The specificity of both antibodies was confirmed by immunoblotting. Thus, we produced two mAb clones against Der f 2 that can be used to create a precise quantitative method to identify allergen components in dust samples and facilitate further study in Der f 2 component-resolved diagnosis (CRD).