Metropolitan Boston Research Articles

Mouse exposure and wheeze in the first year of life

Studies have found that exposure to mice is highly prevalent among children with asthma living in urban areas. To examine the relationship between exposure to mice and wheeze in the first year of life. We conducted an ongoing prospective birth cohort study of 498 children with a history of allergy or asthma in at least 1 parent living in metropolitan Boston (the Home Allergens and Asthma Study). In a multivariate analysis, infants whose parents reported exposure to mice in the household had nearly twice the odds of developing any wheeze in the first year of life as children without exposure (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.14-2.95; P = .01). Other variables associated with wheeze in the first year of life included low birth weight (OR, 1.77; 95% CI, 1.06-2.95; P = .03), having at least 1 lower respiratory tract illness (OR, 5.59; 95% CI, 3.46-9.04; P < .001), exposure to high levels of endotoxin at age 2 to 3 months (fourth quartile compared with first quartile: OR, 2.32; 95% CI, 1.19-4.54; P = .01), and exposure to cockroach allergen of 0.05 U/g of dust or more at age 2 to 3 months (OR, 1.83; 95% CI, 1.09-3.08; P = .02). Among children with a parental history of asthma or allergies, exposure to mice is associated with wheeze in the first year of life, independent of other factors.

Predictors of indoor exposure to mouse allergen in urban and suburban homes in Boston

Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases. To assess indoor mouse allergen exposure in early life among children with parental history of asthma or allergies. Prospective birth cohort study of 498 children with a history of allergy or asthma in at least one parent living in metropolitan Boston. Of the 498 participating children, 357 (71.7%) resided outside the city of Boston and 439 (90.7%) lived in households with incomes > 30,000 dollars. Mouse allergen was detected in 42% of the homes of study participants. In a multivariate analysis adjusting for sex, income, and endotoxin, black race [odds ratio (OR) = 3.0; 95% confidence interval (CI) = 1.3-6.6, P = 0.009], signs of mice in the home at age 2-3 months (OR = 3.0; 95% CI = 1.6-5.6, P = 0.0006), and kitchen cockroach allergen levels > or = 0.05 to < 2 U/g (OR = 1.8; 95% CI = 1.1-3.2, P = 0.02) were associated with detectable mouse allergen in the kitchen. In this model, living in a single detached house was inversely associated with detectable kitchen mouse allergen levels (OR = 0.4; 95% CI = 0.2-0.6, P = 0.0001). Infants with a parental history of asthma or allergies are commonly exposed to mouse allergen in their homes. Among infants at high risk for atopy, predictors of increased mouse allergen levels included black race, reported mice exposure, and moderate levels of cockroach allergen.

Illness Transmission in the Home: A Possible Role for Alcohol-Based Hand Gels

The widespread use of child care has altered the epidemiology of respiratory and gastrointestinal (GI) infection in the community. Our primary objective was to measure transmission of respiratory and GI illnesses among families with children enrolled in child care. We also sought to examine potential predictors of reduced illness transmission in the home in a secondary analysis. We performed an observational, prospective cohort study to determine transmission rates for respiratory and GI illnesses within families with at least 1 child between 6 months and 5 years of age enrolled in child care. A survey about family beliefs and practices was mailed at the beginning of the study. Symptom diaries were provided for families to record the timing and duration of respiratory and GI illnesses. To ensure the accuracy of symptom diaries, biweekly telephone calls were performed to review illnesses recorded by participants. Families with > or =4 weeks of data recorded were included in the analysis. Families were recruited from 5 pediatric practices in the metropolitan Boston area. Of 261 families who agreed to participate in the study, 208 were available for analysis. Secondary transmission rates for respiratory and GI illnesses were measured as illnesses per susceptible person-month. We observed 1545 respiratory and 360 GI illnesses in 208 families from November 2000 to May 2001. Of these, 1099 (71%) respiratory and 297 (83%) GI illnesses were considered primary illnesses introduced into the home. The secondary transmission rates for respiratory and GI illnesses were 0.63 and 0.35 illnesses per susceptible person-month, respectively. Only two thirds of respondents correctly believed that contact transmission was important in the spread of colds, and fewer than half believed that it was important in the spread of stomach flus. Twenty-two percent of respondents reported use of alcohol-based hand gels all, most, or some of the time; 33% reported always washing their hands after blowing or wiping a nose. In multivariate models, use of alcohol-based hand gels had a protective effect against respiratory illness transmission in the home. In homes with young children enrolled in child care, illness transmission to family members occurs frequently. Alcohol-based hand gel use was associated with reduced respiratory illness transmission in the home.

Prevalence and predictors of indoor exposure to mouse allergen in metropolitan Boston

RATIONALE: Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases. Our objective was to assess indoor mouse allergen exposure in early life among children with parental history of asthma or allergies.

Reduction in organic contaminant exposure and resultant hepatic hydropic vacuolation in winter flounder ( Pseudopleuronectes americanus) following improved effluent quality and relocation of the Boston sewage outfall into Massachusetts Bay, USA: 1987–2003

Effluent upgrades for metropolitan Boston have included toxicant reduction, primary and secondary treatment and outfall extension. Between 1992 and 2003 winter flounder at five stations were surveyed annually for liver and muscle burden and chronic hepatic sub-lethal impacts of polynuclear and halogenated aromatic hydrocarbons, and metals. Trends in flounder availability and fin condition were also examined. In 1988 12% of the adult winter flounder in Boston Harbor exhibited hepatic neoplasms and up to 80% had hepatic hydropic vacuolation (HV). Tumor prevalence fell to 0–2% and HV to <50% by 1996. Since then tumors have been absent, while a steady prevalence of HV has persisted, consistent with lower hydrocarbon loading and tissue levels. Contaminants and HV also fell with distance from the Boston outfall. After the outfall extension was activated in 2000, there has been no significant change in flounder liver health at the new outfall site.

The Role of Land Use in Travel Mode Choice: Evidence from Boston and Hong Kong

This article presents a study that analyzed the influence of land use on travel mode choice using survey data from Metropolitan Boston and Hong Kong. In Boston, the focus of inquiry was on whether land use would still matter for mode choice (and if so, to what extent) when mode attributes and traveler socioeconomic characteristics were taken into account. In Hong Kong, where the role of land use in mode choice is obvious due to the densely built environment, the focus was on whether land use completely explained the transit-dominated travel pattern. The empirical modeling confirmed that the role of land use in influencing travel was independent from travel time and monetary costs. Elasticity estimates show that the composite effect of land use on driving could be comparable in magnitude to that of driving cost. Yet being place specific, land use strategies are limited by the spatial extent to which they can be implemented. Land use strategies influence travel more effectively when complemented by pricing policies.

Endotoxin exposure and eczema in the first year of life.

Exposure to endotoxin in early life has been proposed as a factor that may protect against the development of allergic diseases such as eczema. The objective of this study was to examine the relation between endotoxin exposure in early life and eczema in the first year of life in children with parental history of asthma or allergies. This study used a prospective birth cohort study of 498 children who had a history of allergy or asthma in at least 1 parent and lived in metropolitan Boston. A subset of 401 living rooms had house dust samples adequate for analysis of endotoxin. In multivariate analyses adjusting for gender, income, and season of birth, endotoxin levels in the living room at 2 to 3 months of age was inversely associated with physician- or nurse-diagnosed eczema in the first year of life (odds ratio [OR] for each quartile increment: 0.76; 95% confidence interval [CI]: 0.61-0.96). Exposure to a dog in the home at age 2 to 3 months was also inversely associated with eczema in the first year of life, but the CI widened when endotoxin was included in the multivariate model (OR: 0.54; 95% CI: 0.27-1.09). Other variables associated with eczema in the first year of life included paternal history of eczema (OR: 1.91; 95% CI: 1.03-3.55) and maternal specific immunoglobulin E positivity to > or =1 allergen (OR: 1.61; 95% CI: 1.01-2.56). Among children with parental history of asthma or allergies, exposure to high levels of endotoxin in early life may be protective against eczema in the first year of life. In these children, paternal history of eczema and maternal sensitization to at least 1 allergen are associated with an increased risk of eczema in the first year of life.

Description of a clinical pharmacist intervention administered to primary care patients with depression

The objective of this article is to provide a detailed description of interactions between patients with depression and pharmacists. Analysis was conducted on patients from the intervention arm ( n=268) of an randomized controlled trial that evaluated the impact of a clinical pharmacist on the outcomes for depressed primary care patients from nine metropolitan Boston practices. The main outcome measure was the amount of intervention time spent with patients, physicians, and other activities. Details of the behavioral intervention and a categorization of the activities are offered. Pharmacists reported 978 encounters with 268 patients in 6 months. Eighty percent of patient encounters occurred by telephone. Initial encounters took 45 min if in person and 13.3 min if by telephone. Subsequent encounters followed a similar pattern. Follow-up visits occurred 2.3 times per patient. Physician contact took considerably less time. In total, the pharmacist intervention took 70.3 min per patient over 6 months; 42.2% of encounters involved an activity related to non-antidepressant medication and 85% of encounters involved general support. Other activities (education, advocating antidepressants, and motivating adherence) occurred in at least 50% of encounters. Pharmacists repeated intervention activities in the same category approximately two to three times. Interventions to improve the care of depression in primary care patients must anticipate encountering intense needs for information, personal support, and help negotiating the healthcare system. Research that identifies relationships between the components (active ingredients) of an intervention and the outcomes of care will benefit future intervention strategies and contribute to improved and efficient care.

USE OF STAGE DATA TO CHARACTERIZE HYDROLOGIC CONDITIONS IN AN URBANIZING ENVIRONMENT1

ABSTRACT: This paper presents the results of a study on the use of continuous stage data to describe the relation between urban development and three aspects of hydrologic condition that are thought to influence stream ecosystems—overall stage variability, stream flashiness, and the duration of extreme‐stage conditions. This relation is examined using data from more than 70 watersheds in three contrasting environmental settings—the humid Northeast (the metropolitan Boston, Massachusetts, area); the very humid Southeast (the metropolitan Birmingham, Alabama, area); and the semiarid West (the metropolitan Salt Lake City, Utah, area). Results from the Birmingham and Boston studies provide evidence linking increased urbanization with stream flashiness. Fragmentation of developed land cover patches appears to ameliorate the effects of urbanization on overall variability and flashiness. There was less success in relating urbanization and streamflow conditions in the Salt Lake City study. A related investigation of six North Carolina sites with long term discharge and stage data indicated that hydrologic condition metrics developed using continuous stage data are comparable to flow based metrics, particularly for stream flashiness measures.

Relationships between Measures of NOM in Quabbin Watershed

Natural organic matter (NOM) in water sources differs in terms of both character and concentration. Water treatment processes and the aesthetic quality of water may be influenced by NOM concentration and character. NOM is also related to nutrient cycling and availability and the general trophic state of an aquatic ecosystem. Quabbin Reservoir is the primary drinking water source for metropolitan Boston, Massachusetts. Measures of NOM present in samples collected from the watershed included, but were not limited to, total organic carbon (TOC), dissolved organic carbon (DOC), ultraviolet absorbance (UVA), and trihalomethane formation potential (THMFP). Samples were collected at the mouths of the 12 major Quabbin tributaries and from a horizontal transect of six sites within the reservoir. A variation was found in the relationships between measures of NOM from the reservoir and tributary samples. Regression analyses showed positive linear relationships between DOC and UVA, THMFP and TOC, and THMFP and UVA. Relationships between measures of NOM in the reservoir samples were weaker than those obtained for the tributary samples. These weaker relationships were attributed to the low concentrations and narrow ranges of measures of NOM in the reservoir and the overall complexity of the aquatic system.

MICA, HLA-B haplotypic variation in five population groups of sub-Saharan African ancestry.

The human major histocompatibility complex (MHC) class I chain-related gene A (MICA), located 46 kb centromeric to HLA-B, encodes a stress-inducible protein, which is a ligand for the NKG2D receptor. In addition to its primary role in immune surveillance, data suggest that MICA is involved in the immune response to transplants and in susceptibility to some diseases. In this study, 152 subjects from the Yoruba (n=74), Efik (n=32), and Igbo (n=46) tribes of southern Nigeria, 39 nationwide African-American stem cell donors, and 60 African-American individuals residing in the metropolitan Boston area were studied for MICA, HLA-B allelic variation, haplotypic diversity, and linkage disequilibrium (LD). MICA and HLA-B exhibited a high degree of genetic diversity among the populations studied. In particular, MICA allele and HLA-B-MICA haplotype frequencies and LD in the Efik and Igbo tribes were significantly different from the other study groups. HLA-B and MICA loci demonstrated significant global LD in all five populations (P-values &<0.00001). LD also varied in a haplotype-specific manner. A novel MICA allele was detected in the Boston population. These findings are important from an anthropologic perspective, and will inform future HLA-linked disease association studies in related ethnic groups of African-derived ancestry.

Impact of labor induction, gestational age, and maternal age on cesarean delivery rates.

To quantify the impact of labor induction and maternal age on cesarean delivery rates in nulliparous and multiparous women between 36 and 42 weeks' gestation. We performed a retrospective cohort study on 14,409 women delivering at two teaching hospitals in metropolitan Boston during 1998 and 1999. Women who had contraindications to labor, including a prior cesarean delivery, were excluded. The risks for cesarean delivery by induction status, gestational age by completed week between 36 and 42 weeks, maternal age <35, 35-39, and >/=40 years, and stratified by parity, were calculated by logistic regression. In nulliparas, labor induction was associated with an increase in cesarean delivery from 13.7% to 24.7% (adjusted odds ratio [OR] 1.70; 95% confidence interval [CI] 1.48, 1.95]). In multiparas, induction was associated with an increase from 2.4% to 4.5% (OR 1.49; 95% CI 1.10, 2.00). Other variables that placed a nulliparous woman at increased risk for cesarean delivery included maternal age of at least 35 years and gestational ages over 40 weeks. For multiparas, only maternal age 40 years or older and gestational age of 41 weeks were associated with an increase in cesarean deliveries. Induction of labor, older maternal age, and gestational age over 40 weeks each independently increase the risk for cesarean delivery in both nulliparous and multiparous women. Although the relative risk from induction is similar in nulliparas and multiparas, the absolute magnitude of the increase is much greater in nulliparas (11% versus 2.1%).

Fine-tuning the corrosion control targets of alkalinity and pH for Massachusetts Water Resources Authority

Massachusetts Water Resources Authority (MWRA) supplies metropolitan Boston with unfiltered surface water. The source water is corrosive. An interim corrosion control facility came on line in June 1996 to adjust the pH and alkalinity levels for better corrosion control. Copper levels have never been higher than the action limit of 1.3 mg/l and the 90th percentile copper is now less than 0.15 mg/l. The 90th percentile lead level is close to the action level of 0.015 mg/l, but is sometimes still in exceedance. The September 2002 sampling of lead and copper (after the paper was submitted) showed the 90th percentile of lead and copper to be 0.0113 and 0.117 mg/l. MWRA is exploring the option of changing pH and alkalinity targets to meet the lead rule. In addition to lead concerns, other water quality concerns were identified as being sensitive to alkalinity and pH targets. These include, for example, the amount of disinfection by-products formed, the amount of iron released, chloramine stability and nitrification, the buffering capacity of treated water (pH stability), virus inactivation and copper levels in the biosolids from wastewater treatment. The proper target level for pH and alkalinity is a balance between these protective public health and operational goals. Models were developed to assist in fine-tuning the current pH and alkalinity targets of 9.1 and 35 mg/l as calcium carbonate for optimum water quality.

Incorporating Reservoir Transfer into Treatment Optimization Decisions

The Massachusetts Water Resources Authority (MWRA) supplies unfiltered water from two large surface water reservoirs to the metropolitan Boston area, as well as to three smaller communities in central Massachusetts [the Chicopee Valley Aqueduct (CVA) communities]. Quabbin Reservoir is larger than Wachusett Reservoir, and has traditionally been used to supplement the Wachusett during the summer period. Quabbin water is also of better quality, with lower reactive natural organic matter (NOM). The MWRA began to add chlorine at Wachusett in 1997, and a new facility for adding chlorine at Quabbin for the CVA was also started up in 2000 to meet primary disinfection regulations to meet pathogen inactivation. The reaction of chlorine with NOM produces undesirable disinfection by-products (DBPs). The absorption of ultraviolet light at a wavelength of 254 nm was identified in chlorine decay studies to be the most important raw water quality parameter for predicting chlorine decay and DBP formation. This technical note summarizes the chlorine decay model for Wachusett and Quabbin water. The model is extended to ozonation of Wachusett water for the future Walnut Hill treatment plant. The models allowed the development of a trigger using UV-254 to time the Quabbin transfer to optimize treatment results. It is believed that the model for disinfectant decay and the use of UV-254 as a trigger for water treatment decisions are generalized and applicable to other water utilities.

Using sulfur as a tracer of outdoor fine particulate matter.

Six homes in the metropolitan Boston area were sampled between 6 and 12 consecutive days for indoor and outdoor particle volume and mass concentrations, particle elemental concentrations, and air exchange rates (AERs). Indoor/outdoor (I/O) ratios of nighttime (i.e., particle nonindoor source periods) sulfur, PM2.5 and the specific particle size intervals were used to provide estimates of the effective penetration efficiency. Mixed models and graphical displays were used to assess the ability of the I/O ratios for sulfur to estimate corresponding I/O ratios for PM2.5 and the various particle sizes. Results from this analysis showed that particulate sulfur compounds were primarily of outdoor origin and behaved in a manner that was representative of total PM2.5 in Boston, MA. These findings support the conclusion that sulfur can be used as a suitable tracer of outdoor PM2.5 for the homes sampled in this study. Sulfur was more representative of particles of similar size (0.06-0.5 microm), providing evidence that the size composition of total PM2.5 is an important characteristic affecting the robustness of sulfur-based estimation methods.

Are roads and railroads barriers to bumblebee movement in a temperate suburban conservation area?

We investigated how habitat fragmentation affects the movement of marked bumblebees between plant patches in a temperate conservation area in metropolitan Boston, Massachusetts. Our study was conducted on populations of sweet pepperbush ( Clethra alnifolia L. f.) separated by a road and natural woodland, and buttonbush ( Cephalanthus occidentalis L.) separated by a railroad. Bumblebees showed high site fidelity and only rarely crossed roads or railroads. When bees captured at one sweet pepperbush population were moved across a road to a new sweet pepperbush population and released, they returned to their original site, some within 20 min of their capture. When all inflorescences were removed from one sweet pepperbush patch, most bees moved to another sweet pepperbush population on the same side of the road. The results show that while bumblebees have the ability to cross a road and railroad, these human structures may restrict bumblebee movement and act to fragment plant populations because of the innate site fidelity displayed by foraging bees. Moreover, marked bees were almost never observed to move between populations unless they were displaced, or forced to seek additional forage sites.

The role of indoor allergen sensitization and exposure in causing morbidity in women with asthma.

Longitudinal evidence that indoor allergen exposure causes morbidity in sensitized individuals with asthma is scarce. We evaluated the association of allergen sensitization and home exposure to short- and long-term morbidity in 140 women with asthma and to asthma prevalence in 458 women from metropolitan Boston. Cockroach (Blattella germanica), dust mite (Dermatophagoides farinae), and cat (Felis domesticus) allergens in home dust samples, and specific immunoglobulin E antibodies were measured at outset, and doctor-diagnosed asthma and markers of asthma morbidity were ascertained by questionnaire during a 4-year follow-up. Cat- and cockroach-sensitive (immunoglobulin E immunocap [Cap] class > or = 1) women with asthma reported greater morbidity in the past year at the start, and during follow-up, if high levels of the relevant allergen were found. Women with asthma sensitized to cat allergen and with concentrations at 8 microg/g or greater were more likely to have used steroid (adjusted odds ratio [95% confidence interval] 2.7 [1.2-6.2]) and wheezed without a cold (odds ratio 6.8 [3.3- 14.0]) during follow-up. Those sensitized and exposed to cockroach (Bla g 1 or 2 > or = 2 U/g) were at least three times more likely to have used steroid and to have attended a hospital emergency room; the size of the effect upon steroid use was maintained, but the precision was reduced and the 95% confidence interval included one (p = 0.07), with adjustment for race and poverty. We conclude that cockroach and cat allergens may contribute to asthma morbidity in sensitized women.

Reactions to Bolon's "Significance of Test-based Ratings for Metropolitan Boston Schools"

Several concerns are raised abut the procedures used and conclusions drawn in Craig Bolon's article "Significance of Test-based Ratings for Metropolitan Boston Schools" published in this journal as Number 42 of Volume 9.

Atmospheric deposition of polycyclic aromatic hydrocarbons near New England coastal waters

Wet and dry deposition of polycyclic aromatic hydrocarbons (PAHs) was measured at Nahant, Massachusetts, a peninsula jutting into Massachusetts Bay and Wolf Neck, a peninsula jutting into Casco Bay, Maine. Wet deposition (rain and snow) was collected in a funnel which drains into a shielded, temperature controlled receiving bottle. Dry deposition of gaseous and particulate PAHs was collected onto an exposed water surface. PAHs were analyzed by solid phase extraction and gas chromatography-mass spectrometry. Sixteen PAH species were analyzed, ranging from acenaphthylene to coronene. The mean wet deposition rate of the sum of the 16 species is 720 ng m −2 cm −1 precipitation at Nahant, and 831 ng m −2 cm −1 precipitation at Wolf Neck. Wet deposition is attributed to regional PAH emitting sources. Storm patterns appear to bring somewhat higher wet deposition of PAHs to Wolf Neck than to Nahant. The mean dry deposition rate is 95 ng m −2 h −1 at Nahant and 9.3 ng m −2 h −1 at Wolf Neck. The large difference is attributed to the fact that Nahant is close to the urban-industrial metropolitan Boston area and Logan International Airport, whereas Wolf Neck has no major PAH-emitting sources nearby. Individual measurements have an error bracket of ±30%. The Chemical Mass Balance model was used to apportion the dry deposition to source categories. At Nahant, nine samples gave valid statistical attributes with a mean apportionment: jet exhaust 35%, gasoline fueled vehicles 32%, diesel fueled vehicles 17%, wood combustion 13%, others 3%. At Wolf Neck, six samples yielded a mean apportionment: jet exhaust 30%, gasoline vehicles 28%, diesel vehicles 18%, wood combustion 16%, others 8%. There is a considerable variation between the samples. The apportionment is greatly dependent on the quality and selection of the model inputs, i.e. source signatures, which for PAHs are questionable.

Significance of Test-based Ratings for Metropolitan Boston Schools

In 1998 Massachusetts began state-sponsored, annual achievement testing of all students in three public school grades. It has created a school and district rating system for which scores on these tests are the sole factor. It proposes to use tenth-grade test scores as a sole criterion for high school graduation, beginning with the class of 2003. The state is treating scores and ratings as though they were precise educational measures of high significance. A review of tenth-grade mathematics test scores from academic high schools in metropolitan Boston showed that statistically they are not. Community income is strongly correlated with test scores and accounted for more than 80 percent of the variance in average scores for a sample of Boston-area communities. Once community income was included in models, other factors--including percentages of students in disadvantaged populations, (Note 1) percentages receiving special education, percentages eligible for free or reduced price lunch, percentages with limited English proficiency, school sizes, school spending levels, and property values--all failed to associate substantial additional variance. Large uncertainties in residuals of school-averaged scores, after subtracting predictions based on community income, tend to make the scores ineffective for rating performance of schools. Large uncertainties in year-to-year score changes tend to make the score changes ineffective for measuring performance trends.