Project 1

 study was published in the New England Journal of Medicine by CRESSH Project 1 collaborators titled “Air Pollution and Mortality in the Medicare Population.” The nationwide cohort study included 61 million Medicare patients from 2000-2012. The study found that long-term exposure to fine particulate matter (particles less than 2.5 μm in diameter) increases the risk of premature mortality at concentrations lower than the current EPA National Ambient Air Quality Standards (NAAQS). The inclusion of the entire Medicare cohort also allowed for extremely accurate subgroup analyses which showed the highest estimated risk of death from fine particulate matter exposure among male, black, and low-income persons. The study was highlighted in an article on the NPR website and was also featured on NPR’s All Things Considered, which included commentary from Project 1 investigator Francesca Dominici. Read the paper here.

The CRESSH Project 1 (HEAL) team published a study in the September 2017 issue of Epidemiology. The paper titled “Ambient Temperature and Sudden Infant Death Syndrome in the United States” characterizes the association between ambient temperature and Sudden Infant Death Syndrome by analyzing individual-level infant mortality data and outdoor temperature data across the United States.

Sudden Infant Death Syndrome (SIDS) is defined as the unexplained sudden death of an infant less than 1 year old. SIDS is the leading cause of death for infants 1 month to 1 year old and is the third leading cause of overall infant mortality in the US. The rate of SIDS in Massachusetts is greater among black and Hispanic infants than in non-Hispanic white infants. These racial and ethnic disparities in SIDS are of particular concern to CRESSH investigators, who aim to address disparities in health outcomes through their research. While the cause of SIDS is still unknown, overheated bedrooms are known to increase risk due to the limited capabilities of infants to regulate their own body temperature. Because of this, air conditioners as well as good ventilation and airflow in the bedroom can help keep infants from overheating and reduce their risk of SIDS.

To further evaluate the association between ambient temperature and SIDS, Project 1 researchers conducted a national study using infant mortality data from the National Center for Health Statistics and temperature data from the National Oceanic and Atmospheric Administration from 1972-2006 for 210 US cities. They found that the association between temperature and SIDS was highest during the summer among infants 3-11 months old. When the researchers examined racial differences in temperature-related SIDS risk, they found that the percentage increase in SIDS per 10°F increase in ambient temperature was significantly greater among black infants (18.5%) than among white infants (3.6%). The root cause of these racial disparities remains to be determined, but the findings clearly reinforce the need to address SIDS as an environmental health disparities issue and to consider aspects of the home environment that can influence thermal comfort. Overall, these findings indicate that future temperature rises and increased frequency and intensity of heat waves due to climate change may impact infant health. Infants who live in environmental justice communities may be disproportionately impacted by temperature-related health outcomes such as SIDS.

  • Mahalingaiah S, Lane K, Kim C, Cheng J, Hart J (2018). Impacts of Air Pollution on Gynecologic Disease: Infertility, Menstrual Irregularity, Uterine Fibroids, and Endometriosis: a Systematic Review and Commentary. Current Epidemiology Reports.

CRESSH researchers recently published a new paper reviewing the current scientific literature on the impacts of air pollution on reproductive and gynecologic health titled “Impacts of Air Pollution on Gynecologic Disease: Infertility, Menstrual Irregularity, Uterine Fibroids, and Endometriosis: a Systemic Review and Commentary.” The study, published in Current Epidemiology Reports, systematically examined the existing literature in order evaluate the effects of air pollution on various gynecologic diseases, including infertility, menstrual irregularity, uterine fibroids (non-cancerous growths in the uterus), and endometriosis (the development tissues similar to uterine-lining outside the uterus). Based on their review of the literature, the authors found that previous studies focused mainly on fine particulate matter (particles ≤ 2.5 μm in diameter i.e. PM2.5), coarse particulate matter (particles 2.5–10 μm in diameter i.e. PM2.5 -PM10], traffic-related pollutants such as NO2 and other nitrogen oxides, as well as proximity to major roadways. Although some studies found that air pollution due to roadway proximity and other traffic-related exposures impact things like infertility, fertility rates, and menstrual irregularity, the authors concluded that more research is needed in order better understand how air pollution impacts reproductive and gynecologic health in different populations.

  • Yitshak-Sade, M., et al., Neighborhood Greenness Attenuates the Adverse Effect of PM2.5 on Cardiovascular Mortality in Neighborhoods of Lower Socioeconomic Status. International Journal of Environmental Research and Public Health, 2019. 16(5): p. 814.

CRESSH investigators published a study in the International Journal of Environmental Research and Public Health titled “Neighborhood Greenness Attenuates the Adverse Effect of PM2.5 on Cardiovascular Mortality in neighborhoods of Lower Socioeconomic Status.” Air pollution is a well-known risk factor of cardiovascular disease; however, little is known about how land-use characteristics influence the relationship between air pollution and cardiovascular disease. Because of this, the present study aimed to assess if the association between air pollution and cardiovascular mortality is impacted by neighborhood greenness and walkability as well as by neighborhood sociodemographic characteristics, using resident-level mortality data from 2001-2011 from the Massachusetts Department of Public Health. The authors did not find that walkability or greenness significantly impacted the relationship between air pollution and cardiovascular disease overall; however, when they took sociodemographic characteristics into account, they found that greenness decreased the risk of mortality due to cardiovascular disease in more dense areas with a lower percentage of white residents and a higher percentage of residents without a high school diploma. This result aligns with previous studies that have found the health benefits associated with exposure to green space are greater among urban populations of lower socioeconomic status. Possible explanations for this include that increased access to green spaces within vulnerable populations may increase time spent outside, which may contribute to improved physical and mental health. Additionally, access to green spaces may promote social interaction with neighbors and a greater sense of community. The results of this study  suggest that greenness may be an important factor in mitigating the impacts of air pollution and reducing health inequities, particularly among vulnerable populations.

CRESSH researchers published a paper in Environmental Epidemiology titled “Relative toxicities of major particulate matter constituents on birthweight in Massachusetts.” Birthweight is an important predictor of health for newborns, as low birthweight is a known risk factor for conditions such as cardiovascular disease, respiratory disorders, diabetes, and obesity. The association between maternal exposure to PM2.5 (particulate matter less than 2.5μm in diameter) and lower birthweight has been well-established; however, PM2.5 consists of numerous different chemical components and the relative impact of each of those components on birthweight is not known. For this reason, the study team calculated exposure to four major constituents of PM2.5 (elemental carbon, organic carbon, nitrate, and sulfate) at the address of every mother over the course of her pregnancy in Massachusetts from 2001-2012 and estimated the subsequent impact of those exposures on birthweight. The authors found that of the four chemical components of PM2.5 tested, elemental carbon (also known as black carbon) was the most toxic, followed by nitrate, then organic carbon and sulfate. These results could inform more refined air pollution control policies that incorporate the fact that some constituents of particulate matter are more toxic than others.

Project 2

HOME Study investigators published a paper in Environmental Pollution titled “Development of an in-home, real-time air pollutant sensor platform and implications for community use.” The paper provides an overview of what it takes to purchase, build, and maintain all of the components within the Environmental Multi-pollutant Monitoring Assembly (EMMA) that is used to measure indoor air quality in the HOME Study. All of the sensors within EMMA are comparatively low-cost, portable, and measure air pollution in real-time. As the development of low-cost sensors advances, the technology is seemingly becoming more accessible for community-based applications; however, despite their up-front affordability, extensive person-time and expertise are required to select, validate, calibrate, and maintain the devices to ensure reasonable accuracy. Because of financial and resource costs that exceed the cost of the sensors themselves, the authors emphasize that careful consideration should be given by community groups and researchers before the purchase and deployment of these sensors.

Sharing study results with participants is sometimes referred to as “report-back.” Over the last 10-15 years, more environmental health scientists have been getting into the practice of “report-back”, not only when study results have a clear health implications, but also when results are uncertain as to their individual or community impacts. The argument for report-back is that it may improve “environmental health literacy” and empower residents to act. (It also helps inform researchers about the community concern, and impressions of science.) Harvard doctoral student, Kathryn Tomsho, with CRESSH investigators on the Community Engagement Core (CEC) and the HOME Study team, published an evaluation of the report-back in Chelsea, MA. The purpose was to measure how well the intended information was communicated to study participants, and how participant indoor air pollution data was valued by participants. Evaluation data were collected via mail-out questionnaires, in-person meeting participation, post-meeting questionnaires, an anonymous call-line, resulting in qualitative and quantitative data that allowed for “mixed methods evaluation”. The data were evaluated for how well the report back materials and process engaged study participants, enabled participants to comprehend the data, inspired them to take action, and provide information of value to participants. The CRESSH researchers found that there were significant differences between participants who responded to the mail-in questionnaires (i.e., engaged in the report-back) and attended the meeting and those who did not respond at all. People who the team effectively engaged were more likely to have higher education attainment, be of older age, preferred speaking English, and identified as white and non-Hispanic or Latin-x. Of those who engaged, the majority of participants understood and interpreted their survey questions as researchers hoped that they would. Participants who attended the in-person report-back sessions left with a better understanding of their data and health implications than when they arrived. This indicates that there was knowledge gained during the meeting that improved people’s understanding of the data they received, as oppose to what was gleaned from only reading the report back packets. Overall, the CEC and HOME Study teams gathered useful data on how to best focus their efforts to improve understandability and inclusivity of report back sessions for future studies.

Project 3

A study published in Environmental Research by CRESSH MAP-EHD (Project 3) researchers found that despite overall decreases in air pollution, exposure inequalities still persist in Massachusetts. The study, titled “Temporal trends in air pollution exposure inequality in Massachusetts,” used modeled PM2.5 and NO2 concentrations as well as U.S. Census data over an eight year period to look at the drivers and trends of exposure inequality over time. The researchers found the greatest inequalities in air pollution exposure among racial/ethnic groups, with non-Hispanic black and Hispanic populations experiencing disproportionately high concentrations. These disparities were more pronounced in urban areas, potentially due to increased segregation. The ability to examine these inequalities longitudinally allowed for a more in depth look at disparities in air pollution exposure, which may provide future insights into how changes in sociodemographic factors over time may influence things like land-use decisions, policy enforcement, or other factors that impact emissions and pollutant concentrations in different areas. This study was featured in an article by the BU School of Public Health, who also created a video highlighting the study’s findings.

  • Rosofsky A, Levy J, Zanobetti A, Janulewicz P, Fabian MP (2018). The impact of air exchange rate on ambient air pollution exposure and inequalities across all residential parcels in Massachusetts. JESEE.

A paper by the MAP-EHD team was accepted for publication in the Journal of Exposure Science and Environmental Epidemiology titled “The impact of air exchange rate on ambient air pollution exposure and inequalities across all resident parcels in Massachusetts.” Outdoor air can get indoors in multiple different ways, including infiltration through cracks in walls and poorly sealed windows and doors, through natural ventilation (i.e. through open windows), and through mechanical ventilation (i.e. through air conditioners). Air exchange rate (AER) is a measure used to determine how easily outdoor air pollutants can get into buildings. The aim of this study was to estimate AER for homes in Massachusetts based on publicly available data on housing characteristics. The authors used the estimated AER along with outdoor PM2.5 concentrations to determine which homes may experience the greatest ambient air pollution exposures. They found that houses that were located in neighborhoods with higher proportions of Hispanics, had an annual income of less than $20,000, and had individuals with less than a high school degree were more likely to live in leaky homes in areas with higher ambient PM2.5 concentrations. Check back for a link to the full article.

  • Petropoulos Z, Levy J, Scammell MK, Fabian MP (2019). Characterizing community-wide housing attributes using georeferenced street-level photography. JESEE.

Environmental Health doctoral candidate, Zoe Petropoulos, and CRESSH investigators led by Prof. Patricia Fabian (MAP-EHD project) recently published a study on their use of street-level photography to research housing attributes. They developed a new protocol to estimate the prevalence of open windows and air conditioning (AC) units in Chelsea, MA in coordination with GreenRoots, the Chelsea Beautification Committee, and the Chelsea Department of Public Works. Over the course of two 4-hour car rides (in summer and winter), a team of BUSPH student and research assistant volunteers captured 14,000 photos in Chelsea. Zoe then created a crowdsourcing website that paired the photographs of homes with a survey that asked three questions: Are the windows open? One what floor are the open windows located? Is there a window AC on the building? Researchers, family, and friends then answered the survey and the data was used to make descriptive maps of the city. The results showed that: Open windows and AC units were more common during the summer; open windows in the winter were most commonly seen on the top floor; almost 50% of the residences had both open windows and ACs present; AC units were easier to detect than open windows (but applying a grid onto each photo helped in window recording accuracy), and capturing street-view photography from a car was as accurate as capturing photographs by walking.

Related Readings

Project 1: HEAL

PM2.5 and Mortality in 207 US Cities: Modification by Temperature and City Characteristics

Summer Temperature Variability and Long-Term Survival Among Elderly People with Chronic Disease

Susceptibility to Mortality in Weather Extremes Effect Modification by Personal and Small-Area Characteristics

A National Case-Crossover Analysis of the Short-Term Effect of PM2.5 on Hospitalizations and Mortality in Subjects with Diabetes and Neurological Disorders

Changing Patterns of the Temperature-Mortality Association by Time and Location in the US, and Implications for Climate Change

Project 2: HOME

Moving Environmental Justice Indoors: Understanding Structural Influences on Residential Exposure Patterns in Low-income Communities

Environmental Conditions in Low-Income Urban Housing: Clustering and Associations With Self-Reported Health

Indoor Air Quality in Green vs. Conventional Multi-family Low-income Housing

Project 3: MAP-EHD

Incorporating concepts of inequality and inequity into health benefits analysis

Community Engagement

A Walk in the Park: The Influence of Urban Parks and Community Violence on Physical Activity in Chelsea, MA

Meeting People Where They Are: Engaging Public Housing Residents for Integrated Pest Management

Engaging Communities in Research on Cumulative Risk and Social Stress-Environment Interactions: Lessons Learned from EPA’s STAR Program