Book review: Breathtaking: Asthma Care in a Time of Climate Change by Alison Kenner

In Breathtaking: Asthma Care in a Time of Climate Change, Alison Kenner uses a multi-sited ethnography to examine the myriad infrastructures and material practices of care in the United States that mediate the relationship between disordered breathing and the environment. By tracing connections between lived experiences of asthma,environmental conditions and our bodies, the book allows us to imagine new carescapes that could help to make the world more breathable, writes Priyanka deSouza

Book review: Rhodes must fall: the struggle to decolonise the racist heart of empire by Rhodes Must Fall Oxford, edited by Roseanne Chantiluke, Brian Kwoba and Athinagamso Nkopo

In Rhodes Must Fall: The Struggle to Decolonise the Racist Heart of Empire, editors and members of Rhodes Must Fall Oxford Roseanne Chantiluke, Brian Kwoba and Athinagamso Nkopo offer a collection that gives firsthand accounts of the Rhodes Must Fall protests, discusses the response from authorities and explores the practical lessons learned. Grounded in the immense learning of the Fallist movements, this anthology enriches the student movement literature and offer concrete paths forward in the quest to decolonise our institutions, writes Priyanka deSouza

Estimating a Causal Exposure Response Function with a Continuous Error-Prone Exposure: A Study of Fine Particulate Matter and All-Cause Mortality

Numerous studies have examined the associations between long-term exposure to fine particulate matter (PM2.5) and adverse health outcomes. Recently, many of these studies have begun to employ high-resolution predicted PM2.5 concentrations, which are subject to measurement error. Previous approaches for exposure measurement error correction have either been applied in non-causal settings or have only considered a categorical exposure. Moreover, most procedures have failed to account for uncertainty induced by error correction when fitting an exposure-response function (ERF). To remedy these deficiencies, we develop a multiple imputation framework that combines regression calibration and Bayesian techniques to estimate a causal ERF. We demonstrate how the output of the measurement error correction steps can be seamlessly integrated into a Bayesian additive regression trees (BART) estimator of the causal ERF. We also demonstrate how locally-weighted smoothing of the posterior samples from BART can be used to create a more accurate ERF estimate. Our proposed approach also properly propagates the exposure measurement error uncertainty to yield accurate standard error estimates. We assess the robustness of our proposed approach in an extensive simulation study. We then apply our methodology to estimate the effects of PM2.5 on all-cause mortality among Medicare enrollees in New England from 2000-2012

An analysis of degradation in low-cost particulate matter sensors

Low-cost sensors (LCS) are increasingly being used to measure fine particulate matter (PM2.5) concentrations in cities around the world. One of the most commonly deployed LCS is the PurpleAir with about 15,000 sensors deployed in the United States. However, the change in sensor performance over time has not been well studied. It is important to understand the lifespan of these sensors to determine when they should be replaced, and when measurements from these devices should or should not be used for various applications. This paper fills in this gap by leveraging the fact that: 1) Each PurpleAir sensor is comprised of two identical sensors and the divergence between their measurements can be observed, and 2) There are numerous PurpleAir sensors within 50 meters of regulatory monitors allowing for the comparison of measurements between these two instruments. We propose empirically-derived degradation outcomes for the PurpleAir sensors and evaluate how these outcomes change over time. On average, we find that the number of 'flagged' measurements, where the two sensors within each PurpleAir disagree, increases in time to 4 percent after 4 years of operation. Approximately, 2 percent of all PurpleAir sensors were permanently degraded. The largest fraction of permanently degraded PurpleAir sensors appeared to be in the hot and humid climate zone, suggesting that the sensors in this zone may need to be replaced sooner. We also find that the bias of PurpleAir sensors, or the difference between corrected PM2.5 levels and the corresponding reference measurements, changed over time by -0.12 ug/m3 (95% CI: -0.13 ug/m3, -0.11 ug/m3) per year. The average bias increases dramatically after 3.5 years. Climate zone is a significant modifier of the association between degradation outcomes and time.Comment: 28 pages, 5 figures, 4 table

Evaluating the Sensitivity of Mortality Attributable to Pollution to Modeling Choices: A Case Study for Colorado

We evaluated the sensitivity of estimated PM2.5 and NO2 health impacts to varying key input parameters and assumptions including: 1) the spatial scale at which impacts are estimated, 2) using either a single concentration-response function (CRF) or using racial/ethnic group specific CRFs from the same epidemiologic study, 3) assigning exposure to residents based on home, instead of home and work locations. This analysis was carried out for the state of Colorado. We found that the spatial scale of the analysis influences the magnitude of NO2, but not PM2.5, attributable deaths. Using county-level predictions instead of 1 km2 predictions of NO2 resulted in a lower estimate of mortality attributable to NO2 by ~ 50% for all of Colorado for each year between 2000-2020. Using an all-population CRF instead of racial/ethnic group specific CRFs results in a higher estimate of annual mortality attributable to PM2.5 by a factor 1.3 for the white population and a lower estimate of mortality attributable to PM2.5 by factors of 0.4 and 0.8 for Black and Hispanic residents, respectively. Using racial/ethnic group specific CRFs did not result in a different estimation of NO2 attributable mortality for white residents, but led to lower estimates of mortality by a factor of ~ 0.5 for Black residents, and by a factor of 2.9 for to Hispanic residents. Using NO2 based on home instead of home and workplace locations results in a smaller estimate of annual mortality attributable to NO2 for all of Colorado by ~0.980 each year and 0.997 for PM2.5.Comment: 24 pages, 6 figures, 2 table

Reading list: 15 recommended reads on colonial histories, colonial legacies

In this reading list, we recommend fifteen books previously reviewed on the LSE RB blog that critically explore the histories of imperialism, discuss the life and works of people who have contested colonialism and seek to better understand the legacies of empire in the present. If you would like to add to this list, please add your recommendations in the comments below

Spatial variation of fine particulate matter levels in Nairobi before and during the COVID-19 curfew: implications for environmental justice

Abstract: The temporary decrease of fine particulate matter (PM2.5) concentrations in many parts of the world due to the COVID-19 lockdown spurred discussions on urban air pollution and health. However there has been little focus on sub-Saharan Africa, as few African cities have air quality monitors and if they do, these data are often not publicly available. Spatial differentials of changes in PM2.5 concentrations as a result of COVID also remain largely unstudied. To address this gap, we use a serendipitous mobile air quality monitoring deployment of eight Sensirion SPS 30 sensors on motorbikes in the city of Nairobi starting on 16 March 2020, before a COVID-19 curfew was imposed on 25 March and continuing until 5 May 2020. We developed a random-forest model to estimate PM2.5 surfaces for the entire city of Nairobi before and during the COVID-19 curfew. The highest PM2.5 concentrations during both periods were observed in the poor neighborhoods of Kariobangi, Mathare, Umoja, and Dandora, located to the east of the city center. Changes in PM2.5 were heterogeneous over space. PM2.5 concentrations increased during the curfew in rapidly urbanizing, the lower-middle-class neighborhoods of Kahawa, Kasarani, and Ruaraka, likely because residents switched from LPG to biomass fuels due to loss of income. Our results indicate that COVID-19 and policies to address it may have exacerbated existing air pollution inequalities in the city of Nairobi. The quantitative results are preliminary, due to sampling limitations and measurement uncertainties, as the available data came exclusively from low-cost sensors. This research serves to highlight that spatial data that is essential for understanding structural inequalities reflected in uneven air pollution burdens and differential impacts of events like the COVID pandemic. With the help of carefully deployed low-cost sensors with improved spatial sampling and at least one reference-quality monitor for calibration, we can collect data that is critical for developing targeted interventions that address environmental injustice in the African context

Making Air Quality Count: Low-cost sensors, Public Health and Urban Planning

Ambient air pollution is responsible for ~ 4.2 million premature deaths every year making it the world’s single largest environmental health risk. Although 90% of this burden is borne by countries in the Global South, effective air pollution governance and monitoring in many of these countries is lacking. As of 2019, 57 countries had no air quality standards and 108 countries did not have air pollution data in any form. This dissertation attempts to understand and address some of the factors that have resulted in these gaps in data and governance. Specifically, this work makes two main interventions: 1) Low-cost sensors and satellite instruments have immense potential to further our understanding of air pollution, especially in the Global South where little data is available. This thesis develops new methods to derive useful insights about air pollution levels and sources from these technologies. Throughout, it highlights inequalities in production and access to data and these technologies that need to be addressed. 2) Air pollution monitoring practices and governance are intertwined with data infrastructures, political economy conditions, and anticipation of political engagement. This thesis studies the gaps in the data infrastructures and political economy conditions that prevent air pollution science and data from leading to effective regulatory action in the Global South. It uses Kenya as a case study for this work.Ph.D

Book review: Political blackness in multiracial Britain by Mohan Ambikaipaker

In Political Blackness in Multiracial Britain, Mohan Ambikaipaker offers a new ethnographic study using an ‘activist anthropology’ approach that draws on his longstanding association with the grassroots anti-racism organisation Newham Monitoring Project (NMP) to explore the role that political blackness has played in its fight for racial justice and social change. This is an important book, writes Priyanka deSouza, that foregrounds the experiences of those fighting against institutional racism and is generative of new possibilities for forging solidarity

Air pollution in Kenya: a review

Rapid urbanization, the corresponding increase in vehicle ownership, and the continued use of solid fuels as an energy source have resulted in the deterioration of air quality in Kenya. Despite this, there is no publicly available official source of data on air pollution in the country. This article provides an overview of published studies that report the concentrations of widespread ambient pollutants, outline major themes, and identify data gaps. This review reveals that since the 1980’s particulate matter (PM) concentrations in some Nairobi locations, such as the industrial area, have been at dangerously high levels. Almost all of the studies included show that PM concentrations in Nairobi violate the World Health Organization (WHO) guidelines. Moreover, black carbon (BC) concentrations in Nairobi are among the highest in the world, indicating the need for cleaner vehicles in the city. There has been much less work done measuring the levels of gaseous pollutant concentrations in Kenya. Based on these findings, policies to reduce air pollution in Kenya and monitoring strategies to fill in the existing gaps are presented