Chunxia Fu

Allergens in Urban Schools and Homes of Children with Asthma

To cite this article: Permaul P, Hoffman E, Fu C, Sheehan W, Baxi S, Gaffin J, Lane J, Bailey A, King E, Chapman M, Gold D, Phipatanakul W. Allergens in urban schools and homes of children with asthma. Pediatr Allergy Immunol 2012: 23: 543–549.

Exposures to Molds in School Classrooms of Children with Asthma

Students spend a large portion of their day in classrooms which may be a source of mold exposure. We examined the diversity and concentrations of molds in inner‐city schools and described differences between classrooms within the same school.

Perceived neighborhood safety and asthma morbidity in the school inner-city asthma study.

The aim of this study was to investigate whether neighborhood safety as perceived by primary caregivers is associated with asthma morbidity outcomes among inner‐city school children with asthma.

Predictors of indoor exposure to mouse allergen in inner-city elementary schools.

Mouse allergen exposure is prevalent in homes and schools 1–3. While home mouse allergen and predictors of home exposure have been well-characterized, little is known about school environments where children spend the majority of their day 4–6. The ongoing School Inner-City Asthma Study (SICAS; NIH/NIAID) seeks to evaluate the role of school-specific exposures and asthma morbidity in urban students with asthma. In this report, we examined predictors of school-specific mouse exposure for children with asthma. The SICAS study design has previously been reported 7. Briefly, students with asthma were recruited from validated school screening surveys 8. Students who fulfilled established inclusion/exclusion criteria modeled from other urban asthma studies were enrolled 7,9. Classrooms/cafeterias were sampled (settled and airborne) twice during the academic year, approximately 6 months apart (designated as fall and spring, respectively) to assess seasonal differences. Home settled samples were also collected. School and home samples were linked to enrolled students and analyzed for indoor allergens using multiplex array technology (Indoor Biotechnologies, Charlottesville, Virginia). School/classroom and home environment assessments were made by trained research assistants using surveys, inspection forms and questionnaires. The study was approved by the Boston Children’s Hospital Institutional Review Board. School/classroom environment predictor variables analyzed included presence of school basement and signs of mice in the classroom/cafeteria. Home environment predictor variables included signs of mice in the home in the past 12 months and housing type (detached vs. attached). Wilcoxon rank sum test was used to analyze the relation between predictor variables and detectable levels of mouse allergen. When indicated, generalized estimating equation (GEE) models of log-transformed variables accounted for correlation from repeated observations. Analyses were generated using STATA 12 (StataCorp. 2011. Stata Statistical Software: Release 12. College Station, TX:StataCorp LP). Twenty-nine schools participated in the study. Schools were built between 1904–2002, mean age 64.9 years. Mus m 1 settled levels were detectable in 96.8% and 92.3% of school and home samples, respectively, with much higher levels in students’ schools/classrooms than their homes. Bla g 2 settled levels were detectable in only 1.2% of school and 2.9% of home samples, with similar findings seen for Der p 1. In addition, there were virtually no reports of cockroach signs in school classrooms and cafeterias. Table I shows predictors of mouse allergen levels in classrooms, cafeterias and homes. Visible classroom mouse droppings was significantly associated with higher levels of classroom Mus m 1 settled dust in the spring (6.11 vs. 1.21 μg/g, p=0.002) and airborne levels in both the spring and fall (5.25 vs. 2.68 ng/m3, p=0.007; 3.51 vs. 1.20 ng/m3, p=0.04, respectively) (see eFigure 1a/b). Visible cafeteria mouse droppings was significantly associated with higher levels of cafeteria settled levels in the spring (6.50 vs. 0.21 μg/g, p=0.005). The presence of a school basement was predictive of higher cafeteria Mus m 1 airborne levels (1.83 vs. 0.97 ng/m3, p=0.03). Table I Predictors of Mouse (Mus m 1) Allergen Levels in Classrooms, Cafeterias, and Homes Homes of enrolled students with evidence of mice in the past 12 months significantly predicted higher levels of Mus m 1 settled levels (0.30 vs. 0.03 μg/g, p<0.001). Detached one-family homes had a non-significant trend toward lower Mus m 1 settled levels. The goal of this study was to determine whether a relationship exists between inner-city elementary school characteristics obtained by inspection and measured mouse allergen. Identifying predictors of school mouse allergen levels may help tailor intervention strategies towards schools/classrooms likely to have more exposure. To our knowledge, this is the first study looking at predictors of indoor mouse allergen exposure in urban schools of children with asthma. In this study, we found a relationship between signs of mice and higher levels of mouse allergen, mainly in the spring. Mouse allergen levels were higher during the spring season in both classrooms and cafeterias. A plausible explanation is that during the summer months when students are on break, the schools are thoroughly cleaned, thereby, lessening allergen present in the fall season. Moreover, during the colder fall/winter months the mice are likely breeding covertly, resulting in lower allergen levels. During the warmer spring/summer months the mice emerge leading to higher allergen levels but interestingly, the same or less visible droppings. Based on these findings of seasonal variability, the spring season may be a time when more intense integrated pest management (IPM) is necessary to control levels. There may have been less statistical significance for cafeterias than classrooms with respect to visible mouse droppings predicting higher allergen levels given that fewer cafeterias were sampled, resulting in less power. The only statistically significant finding for cafeteria was that signs of mice were predictive of higher settled allergen levels in the spring, consistent with findings seen in the classroom. Interestingly, the presence of a basement did not predict higher classroom allergen levels as would be expected and was only associated with higher cafeteria airborne levels. Similar to previous studies, the reported presence of mice in homes was predictive of higher mouse allergen levels 5,6. However, home allergen levels were much lower than school levels. Housing type did not predict allergen levels although detached one-family homes seemed to have lower levels, consistent with other published findings 4,10. Although we found a significant association between visible classroom mouse droppings and higher mouse allergen levels, it is important to note that there was still a substantial amount of allergen present even when droppings were not seen. Matsui et al. reported more days of asthma symptoms, rescue medication use and a greater risk of asthma-related healthcare use in inner-city Baltimore preschool children exposed to >0.5 μg/g of Mus m 1 in bedroom settled dust 3. Our settled mouse allergen levels exceeded this cut-off even in the groups that did not see mouse droppings. If a Mus m 1 level of >0.5 μg/g is indeed associated with an increase in asthma symptoms and healthcare utilization, then actual measurement of allergen levels may be more informative for assessing asthma morbidity outcomes than relying on reported school characteristics as a surrogate for allergen exposure. This study demonstrated that children with asthma are exposed to significant levels of mouse allergen in inner-city schools. We found that when mouse droppings are seen in the classroom there are much higher levels of settled mouse allergen than if there are no signs of mice. However, even if droppings are not seen there are still significant levels of mouse allergen, >0.5 μg/g of Mus m 1, a level linked to an increase in asthma symptoms and healthcare utilization. Based on our findings, objective sampling in schools may still be necessary to determine the extent of mouse exposure. IPM strategies may need to be more intensely applied in the spring, although year long strategies are likely necessary to tackle this potential public health problem in the school environment.

Agreement between parent and student responses to an asthma and allergy questionnaire in a diverse, inner-city elementary school population.

School-based parent/student screening surveys provide an inexpensive, non-invasive means to identify children at high-risk for asthma1,2. Our goal was to determine parent/student response agreement to an asthma/allergy survey stratified by age and race. We hypothesized that discordance between parent and student responses would increase with age and that ethnicity (particularly generational language differences in Hispanic families) might increase the discordance of parent/student responses. A one page, IRB approved, validated2–6, 20 question parent/student asthma/allergy screening survey available in English and Spanish was distributed to all students in five, northeastern, urban, elementary schools from March to June 2008, as part of the School Inner-City Asthma Study (SICAS). SICAS, a longitudinal school/home environment evaluation of students with asthma and associated morbidity, utilized these surveys to identify potential subjects for the longitudinal study. Students and parents were instructed to fill responses independently. Questions referred to the student’s symptoms including frequency of wheezing, difficulty taking a deep breath, persistent cough, and respiratory problems with activity or at night. Allergy questions focused on frequency of nasal, ocular, or skin symptoms. Response categories were a)never, b)sometimes, c)a lot, d)don’t know. Binary asthma questions ascertained whether there was a previous doctor’s diagnosis of asthma or reactive airway disease, hospitalization for trouble breathing, current asthma medication use and missed days of school due to respiratory problems. Response category options were a)yes, b)no, and c)don’t know. Observations that were missing or answered as “don’t know” were deleted from the analysis. Self-reported race/ethnicity categories were African American, Asian, Hispanic, White, Native American, and Other. Analyses were done using SAS version 9.1 (SAS Institute, Inc., Cary, NC). The percent of agreement was the sum of parent and student responses that agreed divided by the total number of responses. Kappa statistic and McNemar’s test were used to examine agreement beyond expected chance and disagreement, respectively. A test of the difference in proportions was used to determine if there were statistically significant differences between age groups and race. 707 parent/student pair surveys were analyzed. The students’ ages ranged from 5 to 15 years average 8.66±1.96 (standard deviation). The cohort was predominantly Hispanic (54%) and African American (27%). Overall agreement ranged from 81% to 98% for all questions (Kappa of 0.59 to 0.94), except for one. The question, “develops a cough that won’t go away?” had 62% agreement (Kappa of 0.31), demonstrating fair agreement. Table 1 shows the parent/student responses to identical questions by age and race. Direction of disagreement was due to student affirmative responses. Table categories: No/No, No/Yes, Yes/No, and Yes/Yes demonstrate parent/student pairs that responded in this manner. Column 3 (No/No) and column 6 (Yes/Yes) demonstrate parent/student agreement. Column 4 and 5 (No/Yes and Yes/No) demonstrate response disagreement. The kappa statistic decreased and disagreement level increased with age, with similar results by race, but none of these were statistically significant. Table 1 Parent and student responses to survey questions regarding the student’s symptoms. Responses to binary asthma questions demonstrated 93%–97% agreement, with good to excellent Kappa (0.75–0.91). Quantitative asthma symptoms demonstrated 81%–86% agreement, with a moderate to good Kappa (0.59–0.7). Chest tightness or cough after activity or night wakening demonstrated 81%–86% agreement, with a moderate to good Kappa (0.59–0.67). Overall, student responses matched their parents’ regarding quantitative asthma questions. The most concordant response was seen in asthma medication use (97% agreement, 0.91 Kappa), diagnosis of asthma (96% agreement, 0.89 Kappa), hospitalization for respiratory problems (94% agreement, 0.78 Kappa), and missed school days due to breathing problems (93% agreement, 0.75 Kappa), indicating both parents and students have good recognition of the student’s condition. Discordant responses to the question, “develops a cough that won’t go away?” may indicate unclear wording, misinterpretation, or that students may be more in tune with their daily symptoms. Decreased agreement with increasing age may occur due to increased time older students are away from their caregivers. Persistent, indolent symptoms may go unnoticed by the parent, but have significant effects on the child. In contrast, good agreement was seen on hospitalizations or missed school day responses as these likely affect both parties. Parent/student agreement in responses did not differ by race/ethnicity or language of questionnaire (English or Spanish). Our study generally showed good agreement between parent/student responses for asthma. Disagreement was seen most in responses to questions that were more dependent on self-perception of symptoms but these were not statistically significant. Also, no significant racial/ethnic/language differences in parent/student agreement were seen. This study suggests that screening surveys given to either parent or elementary students may be a simple, cost-effective mechanism for identifying children in an urban school population who may need further evaluation.