The Impact of Fast-Food Density on Obesity during the COVID-19 Lockdown in the UK: A Multi-Timepoint Study on British Cohort Data

Poor food environments are considered to trigger obesity and related health complications by restricting the local food options to predominantly low quality, energy-dense foods. This study investigated the impact of the food environment on obesity with a focus on any changes that might have occurred around the COVID lockdown period in the UK when majority of the population relied on food delivery and the local food environments. The proportion of fast-food retailers in the area and the Retail Food Environment Index (RFEI) were calculated for participants of the 1970 British Cohort Study (BCS70) at three timepoints: pre-COVID (2016), the first UK nation-wide lockdown (April–May 2020) and post lockdown (September–October 2020). The association of the food environment and the odds of obesity was estimated through multivariable logistic regression, with adjustments being made for selected socioeconomic variables. A model using the fast-food proportion as the sole predictor estimated that higher fast-food proportion increased the odds of obesity by 2.41 in 2016, 2.89 during the lockdown and 1.34 post lockdown, compared with 1.87, 2.23, and 0.73, respectively, for the same three periods with adjustments being made for select socioeconomic variables. On the other hand, RFEI increased the odds of obesity only slightly at 1.01, 1.02 and 1.03, respectively, with the model with adjustments yielding respective similar values. The fast-food proportion model indicates that proximity to a poor food environment is linked to obesity, especially during the COVID lockdown period, but the impact of a poor-food environment is limited if the RFEI is used as its indicator. The findings will add much needed insights on the UK data and will inform public health planning and policy.

Comparison of work efficiency in factory workers: pre & post covid lockdown - a cross sectional study.

BACKGROUND: The COVID-19 pandemic's impact on economies worldwide has caused changes in work patterns, reduced productivity, and job losses, particularly affecting factory workers. Lockdown measures have also led to reduced physical activity levels, which is a significant risk factor for chronic diseases. This study aims to investigate efficiency of factory workers pre and post lockdown periods. The findings will contribute to identifying evidence-based strategies to minimize the negative impact of lockdown measures on factory workers' productivity and health. MATERIALS AND METHODS: A cross-sectional study was conducted to assess the work performance of employees in a medicine manufacturing unit. Data was collected from factory workers online and study period was January 2021 to April 2022. Survey includes close ended questions regarding work performance of employees before lockdown period (Before 20/03/2020) and performance after lockdown period (After August 2020). The sample size of 196 employees selected through simple random sampling. A questionnaire consisting of demographic factors, work details, and work performance was prepared using pretested standard tools, including the Individual Work Performance Questionnaire (IWPQ), the World Health Organization Health and Work Performance Questionnaire (HPQ), and the Stanford Presenteeism Scale (SPS-6). The collected data was analysed using descriptive statistics and a paired t-test. RESULTS: The study found that prior to lockdown, 99% of employees consistently had higher performance, with 71.4% ranking in the top 10. However, after lockdown, the percentage of employees with high performance decreased to 91.8%, with only 63.3% ranking in the top 10. These differences were statistically significant, indicating a decrease in work efficiency of 8.1%. Before lockdown, employees worked longer hours, including on off days, while after lockdown, a small proportion missed work due to various reasons, resulting in better quality work. CONCLUSION: In conclusion, the study highlights the significant impact of the COVID-19 pandemic on the work efficiency of factory workers. The findings indicate a decrease in work efficiency after the lockdown, coupled with an increase in employee stress. This suggests that the pandemic has brought about unique challenges for factory workers that need to be addressed to maintain their well-being and productivity. This study emphasizes the importance of creating a supportive work environment that prioritizes the mental and physical health of employees, especially during times of crisis.

Spatiotemporal analysis of retail: pre- and post-COVID dynamics in Gros, San Sebastian

The decrease of commercial activity that has been occurring in the last decade has recently accentuated by the COVID pandemic, affecting the livability of cities and public space. This paper analyzes the ground floor activities in Gros neighbourhood, in San Sebastian, Spain, observing both its temporal evolution and its spatial distribution. The study performs two in situ geolocation data collections in January and August 2020, immediately before and after the COVID lockdown in Spain. Through the collected data, it analyzes the distribution and evolution of ground floor space dedicated to public activities. The study concludes that the activities suffered a decrease of 1.8% in the analyzed period, and that activities located on pedestrianized streets or with fewer lanes have had fewer closures. The work also shows which efforts are needed for in situ data collection to guide urban policy. © 2022 Prensas de la Universidad de Zaragoza. All rights reserved.

COVID-19 and early puberty-An unintended consequence of COVID-19 lockdown?

The novel coronavirus (SARS-CoV-2) causes the disease COVID-19, also termed as acute atypical pneumonia leading to respiratory failure. Children were more likely to spend time at home due to the lockdown mandated by governments as a preventive measure, which led to alterations in dietary habits and sleeping patterns which could have had a substantial influence on their sexual development, including but not limited to faster onset of puberty. Existing data suggested a plausible relationship between COVID-19 and early puberty. Obesity, physical activity, mental health, and birth weight are major risk factors that have further contributed to the early onset of puberty. In order to address such health crises affecting children, comprehensive solutions are urgently required. As COVID-19 continues to have multiple unpredictable health consequences, spreading awareness regarding this specific problem is of paramount importance.

Diversity rhythm in pontellid copepods (Pontellidae: Copepoda) from the Covelong coast pre-and post-COVID-19 lockdown, Bay of Bengal

Copepods act as indicators of the aquatic ecosystem since they rapidly respond to changes in nutrient content of the environment. Plankton samples were collected for two years from the Covelong coast, India (January to December 2019 and January to December 2021). The diversity patterns of pontellid copepods before and after the COVID-19 lockdown were analyzed. Physicochemical parameters like temperature, salinity, pH, dissolved oxygen, calcium, magnesium, nitrite, phosphate, and ammonia level for both years were measured to compare and contrast the coastal health before and after the lockdown. Six species of pontellid copepods were reported before the lockdown period and 10 species were reported after the lockdown. Physicochemical parameters like ammonia, nitrite, and phosphate levels were reduced after the lockdown. Temperature and nitrite showed a considerable negative correlation with pontellid copepods (–0.749 and –0.782), whereas dissolved oxygen showed a high positive correlation (0.732). Regression analysis was carried out to emphasize the relationship between pontellid copepods with the environment. The regression (R2) coefficient with temperature, nitrite, and dissolved oxygen were 0.571, 0.682, and 0.636, respectively. However, high species diversity was observed in February during both pre-and postlockdown periods. Redundancy analysis was used to visualize the relationship between the pontellid copepods and physicochemical parameters. The density of pontellid copepods and the level of physicochemical parameters greatly fluctuated throughout the entire study period and showed variation in density and diversity. © TÜBÍTAK.

Predicting Order Processing Times in E-Pharmacy Supply Chains During COVID Pandemic Using Machine learning—A Real-World Study

The purpose of this paper is to solve the problem of processing time prediction for orders for medical supplies placed through a large real-world e-Pharmacy—in a post-COVID-lockdown world—using artificial intelligence (AI) and machine learning (ML) techniques. We use an ensemble of ML regressors to predict the processing times of orders for medical supplies and an ensemble of ML classifiers to predict the shipment times of deliverables. We use intelligent model stacking methods to obtain performance improvements for our models. On exact match performance measurement scheme, our solution produces 548.49%, and on a 3-day range performance measurement scheme, our solution produces 25% improvement over the existing statistical solution implemented at the said e-Pharmacy. This is an important problem because when an e-Pharmacy can predict in advance the time elapsed between medical order placement and the time the order gets shipped out, the said e-Pharmacy can implement measures and controls to optimize the speed of fulfillment. We are one of the first to study real-world e-Pharmacy supply chain from the perspective of order processing time prediction under post-COVID-19-lockdown conditions and come up with a novel ML ensemble stacking approach to make predictions. The value this work provides is that we have shown that the adoption of AI and ML techniques in e-pharmacy supply chains would result in infusing certainty in the supply of therapeutics in these uncertain COVID lockdown times. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Psychological impact of a country-wide lockdown. Role of personal, behavioral, social, and physical conditions on negative and positive affect and meaning in life

During the early outbreak of COVID-19 in 2020, a strict home lockdown was maintained in Spain for more than 50 days, disrupting social and economic activities. The aim of this study is to explore affective and well-being responses during the initial period of mandatory home lockdown. Specifically, we analyzed: 1) differences in risk perception according to sociodemographic and health profile;2) relation between social and environmental characteristics of home isolation, positive and negative affect and meaning in life;and 3) the relationship between activities and behaviors performed by people under lockdown and well-being. A total of 1343 Spanish residents participated in this correlational and cross-sectional study. Results show a significant relationship between health and economic risk perception associated with confinement. Higher health risk perception was identified among the older population and those belonging to high-risk groups. High resilience was linked to lower negative affect and greater positive affect and meaning in life. Regarding social and environmental characteristics of home isolation, people living with others reported greater negative affect than people living alone and the daily frequency of use of open-air spaces was linked to positive affect. Higher positive affect and meaning in life were also reported in people who frequently participated in community activities or by helping others. Lower negative affect was only associated with physical exercise. © 2022, Sociedad Interamericana de Psicologia. All rights reserved.

Associations between screen use, outdoor time/daylight exposure and sleep changes during the first COVID-19 lockdown in French children from the ELFE and EPIPAGE2 birth cohorts.

AIMS: To investigate associations between outdoor and screen time and changes in sleep patterns in children from two nationwide birth-cohorts in the SAPRIS project. METHODS: During the first French COVID-19 pandemic lockdown, volunteer parents of children enrolled in the ELFE and EPIPAGE2 birth-cohorts completed online questions about their child's outdoor time, screen time, and changes in sleep duration and quality compared with the pre-lockdown situation. In 5700 children (aged 8-9 years, 52% boys) with available data, we assessed associations between outdoor time, screen time, and sleep changes using multinomial logistic regression models adjusted for confounders. RESULTS: Children spent on average 3 h08 outdoors and 4 h34 using screens/day (3 h27 for leisure, 1 h07 for class-work). Sleep duration increased in 36% of children and decreased in 13.4%; sleep difficulties appeared/increased in 22.5% and decreased/disappeared/remained stable in 18.3%. After adjustment, increased screen time, especially for leisure, was associated with increased and decreased sleep duration (OR(95%CI) = 1.03(1.00-1.06) and OR = 1.06(1.02-1.10), respectively). No association was observed between outdoor time and sleep changes after adjustment. CONCLUSIONS: Our study adds evidence for the association between high leisure-time screen time and shorter sleep time. It supports current screen guidelines for children, especially during leisure time and for those whose sleep duration is short.

True Reduction in the Air Pollution Levels in the Community of Madrid During the COVID-19 Lockdown

The coronavirus disease (COVID) lockdown was implemented in 2020, which included harsh restrictions on the amount of traffic. As a consequence, a low-emission scenario that could only be simulated before, actually occurred. This constituted a unique and valuable opportunity to study the effect of air quality pollutant concentrations. Although a direct comparison between the observed measured values given by reference air quality stations (AQSs) and values from before the COVID lockdown provides an idea of the pollution reduction, it cannot be separated from the meteorology, and hence, those studies could be misleading. This study used the approach of modeling a normal business day using both air quality and meteorological data from 2017 to 2019 to train machine-learning models to be able to predict what concentration of the three most concerning pollutants (NO2, O-3, and PM10) would be given by the meteorological conditions and the time of the year. The XGBoost and LightGBM gradient boosting decision tree-based models were applied to the time series recorded in Madrid and used to predict the expected concentrations in 2020 if no restrictions had been made. The predictions could then be compared to the real observed AQS data to determine the meteorological normalized reductions. The results showed around a 60% reduction in the NO2 at the three types of AQSs (traffic, suburban, and background) during the most restrictive months of the pandemic. The O-3 concentration showed a different behavior depending on the type of AQS, pointing to changes in the regime of other pollutants, such as VOCs. The PM10 was the most difficult case to analyze because of its dependence on external transport phenomena, which were difficult to consider in the models. A set of CTM simulations should be done in the future to assess the O3-VOCs-NOx chemistry.

Need Of Psychologists And Counsellors In Educational Settings Post Covid Lockdown: India

This research is focused upon the need of psychologists and counsellors in educational institutes after the Coronavirus (COVID-19) pandemic lockdown. According to the United Nations, education is described as a "basic human right, a worldwide shared asset, and a major driver of progression throughout all 17 Sustainable Development Goals (SDGs) of the 2030 Agenda as a foundation of fair, egalitarian, inclusive, and harmonious communities". The COVID-19 pandemic has been subtitled as a "black swan" event which was very unpredictable yet came with severe consequences. It has been equated to Second World War in aspects of socio-economic outcomes and has brought tremendous and serious impeding of education. It made a nearly ubiquitous influence on pupils and educators all over the globe. For more than one year, schools, colleges and universities have remained closed, which has resulted in extreme muddling of the education system. With the recommencement of academic establishments, a wave of frustration, anxiety and depression has consumed many teachers, pupils, and parents. The experience of comfort of homes and lack of socialisation has left students (especially small children) with feelings of edginess towards physically being present and studying in classrooms. Therefore, professional individuals such as psychologists who can help manage, regulate and uplift the whole education system of the present scenario, while providing solutions to the general problems such as difficulty in learning among students and mental health issues that are often ignored, are a desideratum. Copyright © 2022, Anka Publishers. All rights reserved.

Disequilibrium propagation of quantity constraints: application to the COVID lockdowns

This paper develops a network economy model to study the propagation of the COVID lockdown shock. Firms are related to each other through buyer-seller relations in the market for intermediate inputs. Firms choose production levels and input combinations using prices that emerge from local interactions. Nothing forbids trade at out-of-equilibrium prices. In such a setting, disequilibrium spills over from one market to another due to the interconnections between markets. These disequilibrium dynamics are capable of generating unemployment when workers released by contracting firms are not frictionlessly absorbed by expanding firms. We calibrate the model to the US economy using a data set with more than 200,000 buyer-seller relations between about 70,000 firms. Computational experiments on the calibrated economy suggest that the COVID lockdown generates a sizeable decline in GDP. The endogenously generated unemployment dynamics is a primary determinant of the cost of the lockdown.

COVID-19 Pandemic Lockdown: A Cloud with a Silver Lining for the Road Traffic Accidents Pandemic.

Context: Effects of coronavirus disease 2019 (COVID-19) pandemic lockdown on road traffic accidents (RTAs) in Chhattisgarh, India. Background: Most neurosurgical emergencies are from brain and spine trauma. RTA is the leading cause of such injuries. While the nationwide lockdown was an extreme measure to control the COVID pandemic, it influenced the overall road traffic dynamics and neurotrauma. Objective: This study aims to assess the impact of the lockdown on neurotrauma. Methods and Materials: This retrospective study included all patients with brain and spine injuries who were admitted between January 17th and May 31st, 2020. The study population was divided into prelockdown (PL) and lockdown (L) groups. Results: Of the 668 patients, 436 were placed in the PL and 232 in the L group. The mean ages were 36.34 (SD = 17.96) and 35.98 (SD = 16.93), respectively. Male to female ratios were 82.3:17.7 in the PL group and 79.7:20.3 for the L group. RTA-related injuries were significantly lower during the lockdown period (n = 335 PL vs. 162 L [P = 0.048]). During the lockdown, there were more mild injuries (25.91% PL vs. 36.63% L) and less severe injuries (33.25% PL vs. 18.96% L [P = 0.0002]). Mortality was significantly less (P = 0.029) during the lockdown (n = 48 L vs. 124 PL). The proportion of RTA-related neurotrauma cases increased (33.33% L1, 57.14% L2, 73.13% L3, and 80.39% L4) with each phase of lockdown (L1-L4). Conclusions: During the lockdown period, the number of trauma cases had decreased, with a significant decrease in RTA-related admissions, along with their severity and mortality. The number of trauma cases and their severity increased gradually with each phase of lockdown.

Incidence of Isolated Biliary Atresia during the COVID Lockdown in Europe: Results from a Collaborative Project by RARE-Liver.

BACKGROUND: Biliary atresia (BA) is a rare cholangiopathy where one of the proposed aetiological mechanisms is an infectious viral trigger. Coronavirus disease-19 (COVID) lockdown restrictions were implemented to reduce the transmission of infections. Strictness of lockdown varied across European countries. This study aimed to investigate if there was an association between strictness of lockdown and change in isolated BA (IBA) incidence in Europe. METHODS: We approached European centres involved in the European Reference Network RARE-LIVER. We included IBA patients born between 2015 and June 2020. We calculated the number of IBA patients born per centre per month. The Stringency Index (SI) was used as lockdown strictness indicator. The association between percentage change of mean number of IBA patients born per month and the SI was assessed. RESULTS: We included 412 IBA patients from thirteen different centres. The median number of patients per month did not change: 6 (1-15) pre-lockdown and 7 (6-9) during lockdown (p = 0.34). There was an inverse association between SI and percentage change in IBA (B = -0.73, p = 0.03). Median age at Kasai portoenterostomy (days) did not differ between time periods (51 (9-179) vs. 53 (19-126), p = 0.73). CONCLUSION: In this European study, a stricter COVID-lockdown was seemingly accompanied by a simultaneous larger decrease in the number of IBA patients born per month in the lockdown. Results should be interpreted with caution due to the assumptions and limitations of the analysis.

Improved air quality leads to enhanced vegetation growth during the COVID-19 lockdown in India.

The direct effect of pandemic induced lockdown (LD) on environment is widely explored, but its secondary impacts remain largely unexplored. Therefore, we assess the response of surface greenness and photosynthetic activity to the LD-induced improvement of air quality in India. Our analysis reveals a significant improvement in air quality marked by reduced levels of aerosols (AOD, -19.27%) and Particulate Matter (PM 2.5, -23%) during LD (2020)from pre-LD (March-September months for the period 2017-2019). The vegetation exhibits a positive response, reflected by the increase in surface greenness [Enhanced Vegetation Index (EVI, +10.4%)] and photosynthetic activity [Solar Induced Fluorescence (SiF, +11%)], during LD from pre-LD that coincides with two major agricultural seasons of India; Zaid (March-May) and Kharif (June-September). In addition, the croplands show a higher response [two-fold in EVI (14.45%) and four-fold in SiF (17.7%)] than that of forests. The prolonged growing period (phenology) and high rate of photosynthesis (intensification) led to the enhanced greening during LD owing to the reduced atmospheric pollution. This study, therefore, provides new insights into the response of vegetation to the improved air quality, which would give ideas to counter the challenges of food security in the context of climate pollution, and combat global warming by more greening.

Dietary Patterns and Dietary Recommendations Achievement From Latin American College Students During the COVID-19 Pandemic Lockdown

This study aimed to compare the diet quality of different dietary patterns among college students from Latin American countries, including vegetarians, vegans, and omnivores during the COVID-19 pandemic. A cross-sectional, observational, multicenter study was conducted including a non- probabilistic sample of university students from 10 countries. University students were invited to participate in the study through social network platforms. Participants were self-reported to have followed a specific dietary pattern;either the Prudent diet, Western diet, Ovo-dairy-vegetarian diet, Fish-vegetarian diet, Strict vegetarian diet (vegan) or other. The last three patterns (vegetarians and vegans) were grouped as following a plant-based diet. A self-assessment survey was used to evaluate healthy eating habits using a questionnaire with values between 1 (do not consume) and 5 (consume) for a total of 9–45 points (higher values represent better eating habits). Unhealthy habits were assessed with nine questions. A total of 4,809 students filled out the questionnaire, and the majority of them were females (73.7%). A high percentage have been in lockdown for more than 5 months and were in lockdown when the survey was released. 74.3% were self-reported to follow a prudent diet, while 11.4% reported following a western dietary pattern and 8.8% a plant-based diet. When compliance with healthy and unhealthy dietary habits was analyzed, although all groups had low compliance, the plant-based diet group (56.09 ± 6.11) performed better than the Western diet group (48.03 ± 5.99). The total diet quality score was significantly higher for plant-based diet followers, who also tended to better achieve the recommendations than omnivorous students, especially the ones following a western diet. These results present evidence that young adults such as college-aged students have unhealthy dietary habits. However, the ones who follow a plant-based diet such as vegetarians and vegans exhibit better scores and healthier dietary conducts. Copyright © 2022 Murillo, Gómez, Durán-Agüero, Parra-Soto, Araneda, Morales, Ríos-Castillo, Carpio-Arias, Cavagnari, Nava-González, Bejarano-Roncancio, Núñez-Martínez, Cordón-Arrivillaga, Meza-Miranda, Mauricio-Alza and Landaeta-Díaz.

A large-scale real-world comparative study using pre-COVID lockdown and post-COVID lockdown data on predicting shipment times of therapeutics in e-pharmacy supply chains

Purpose The purpose of this study is to present a large-scale real-world comparative study using pre-COVID lockdown data versus post-COVID lockdown data on predicting shipment times of therapeutic supplies in e-pharmacy supply chains and show that our proposed methodology is robust to lockdown effects. Design/methodology/approach The researchers used organic data of over 5.9 million records of therapeutic shipments, with 2.87 million records collected pre-COVID lockdown and 3.03 million records collected post-COVID lockdown. The researchers built various Machine Learning (ML) classifier models on the two datasets, namely, Random Forest (RF), Extra Trees (XRT), Decision Tree (DT), Multi-Layer Perceptron (MLP), XGBoost (XGB), CatBoost (CB), Linear Stochastic Gradient Descent (SGD) and the Linear Naive Bayes (NB). Then, the researchers stacked these base models and built meta models on top of them. Further, the researchers performed a detailed comparison of the performances of ML models on pre-COVID lockdown and post-COVID lockdown datasets. Findings The proposed approach attains performance of 93.5% on real-world post-COVID lockdown data and 91.35% on real-world pre-COVID lockdown data. In contrast, the turn-around times (TAT) provided by therapeutic supply logistics providers are 62.91% accurate compared to reality in post-COVID lockdown times and 73.68% accurate compared to reality pre-COVID lockdown times. Hence, it is clear that while the TAT provided by logistics providers has deteriorated in the post-pandemic business climate, the proposed method is robust to handle pandemic lockdown effects on e-pharmacy supply chains. Research limitations/implications The implication of the study provides a novel ML-based framework for predicting the shipment times of therapeutics, diagnostics and vaccines, and it is robust to COVID-19 lockdown effects. Practical implications E-pharmacy companies can readily adopt the proposed approach to enhance their supply chain management (SCM) capabilities and build resilience during COVID lockdown times. Originality/value The present study is one of the first to perform a large-scale real-world comparative analysis on predicting therapeutic supply shipment times in the e-pharmacy supply chain with novel ML ensemble stacking, obtaining robust results in these COVID lockdown times.

Constructivist teaching and learning with technologies in the COVID-19 lockdown in Eastern India.

This paper reports a study on teaching and learning strategies during the COVID-19 lockdown period (CLP) that were used by the secondary government school teachers and students in Eastern India. These teaching and learning strategies were analysed in relation to their engagement with an initiative called Integrated approach to Technology in Education (ITE). ITE engagement in the pre-CLP involved using project-based learning (PBL) with technology and continuous, practise-based professional development for teachers focusing on integrating constructivist use of technology in their curriculum and pedagogy. A survey and interviews of teachers revealed that teachers with higher ITE engagement in the pre-CLP were more likely to use PBL with technology during the CLP. Students' interviews indicated that this PBL involved deep research and technical skills that were also practised during the CLP using distance technologies. Thus, the study demonstrated adaptation of ITE innovation into a distance mode; the introduction of WebQuests during the CLP improved the likelihood of teachers engaging in project-based teaching and PBL during the CLP. Policymakers, practitioners and researchers are recommended to adopt and continue to study the sustainability of ITE approach in new contexts such as the CLP.

Personal exposure monitoring of PM2.5 among US diplomats in Kathmandu during the COVID-19 lockdown, March to June 2020.

The 2019 Novel Coronavirus SARS-CoV 2 (COVID-191) pandemic has severely impacted global health, safety, economic development and diplomacy. The government of Nepal issued a lockdown order in the Kathmandu Valley for 80 days from 24 March to 11 June 2020. This paper reports associated changes in ambient PM2.5 measured at fixed-site monitors and changes in personal exposure to PM2.5 monitored by APT Minima by four American diplomats who completed monitoring before and during lockdown (24 h for each period per person, 192 person-hours in total). Time activities and use of home air pollution mitigation measures (use of room air cleaners (RACs), sealing of homes) were recorded by standardized diary. We compared PM2.5 exposure level by microenvironment (home (cooking), home (other activities), at work, commuting, other outdoor environment) in terms of averaged PM2.5 concentration and the contribution to cumulative personal exposure (the product of PM2.5 concentration and time spent in each microenvironment). Ambient PM2.5 measured at fixed-sites in the US Embassy and in Phora Durbar were 38.2% and 46.7% lower than during the corresponding period in 2017-2019. The mean concentration of PM2.5 to which US diplomats were exposed was very much lower than the concentrations of ambient levels measured at fixed site monitors in the city both before and during lockdown. Within-person comparisons suggest personal PM2.5 exposure was 50.0% to 76.7% lower during lockdown than before it. Time spent outdoors and cooking at home were large contributors to cumulative personal exposure. Low indoor levels of PM2.5 were achieved at work and home through use of RACs and measures to seal homes against the ingress of polluted air from outside. Our observations indicate the potential reduction in exposure to PM2.5 with large-scale changes to mainly fossil-fuel related emissions sources and through control of indoor environments and activity patterns.