Dataset of aggregated indoor and outdoor daily environmental variables for three school sites impacted by air purifiers

This dataset contains indoor and outdoor air quality measurements, along with environmental parameters, collected through low-cost sensors between November 2023 and June 2024 at 3 school locations of interest in the city of Milan, Italy. Indoor values from multiple low-cost sensors have been aggregated to a unique value at the daily level for each location. Note that in each location, professional air purifiers were located in some indoor environments where measurements were taken. Outdoor pollution levels are sourced from the European Environmental Agency (EEA) database. We interpolate daily averages of fine particulate matter (PM2.5) and hourly averages and maxima of ozone (O3) measured at the two closest background air quality stations to each location of interest by applying inverse distance weighting. They provide indicative levels of pollution at the city level. ---Variable Name Descriptionid: Unique identifier of location to which the environmental data referdate: Timestamp of the daily observation (format: YYYY-MM-DD)ind_pm25: Daily indoor fine particulate matter (PM2.5) concentration in micrograms per cubic meter (µg/m³)ind_pm10: Daily indoor coarse particulate matter (PM10) concentration (µg/m³)ind_co: Daily indoor carbon monoxide (CO) concentration in parts per million (ppm)ind_co2: Daily indoor carbon dioxide (CO2) concentration (ppm)ind_temperature: Daily indoor air temperature in Celsius degrees (°C)ind_humidity: Daily indoor relative humidity in percentage (%)ind_pressure: Daily indoor atmospheric pressure in hectopascals (hPa)out_mean_pm25: Daily outdoor average PM2.5 concentration (µg/m³) from nearby air quality stationsout_mean_o3: Daily outdoor average ozone (O3) concentration (µg/m³)out_max_o3: Daily outdoor maximum hourly ozone (O3) concentration during the day (µg/m³)本数据集收录了2023年11月至2024年6月期间，在意大利米兰市3处选定学校点位通过低成本传感器采集的室内外空气质量与环境参数监测数据。各点位的多台低成本传感器所获取的室内监测值，已被聚合为单日统一均值。需注意：各点位的部分监测室内环境中部署了专业空气净化器。 室外污染水平数据源自欧洲环境署（European Environmental Agency, EEA）数据库。本研究通过反距离加权法，针对各选定点位，对其周边最近的2个背景空气质量监测站所测得的细颗粒物（fine particulate matter, PM2.5）日均值、臭氧（O3）小时均值与小时最大值进行插值计算，以此提供城市尺度的污染指示水平。 ### 变量名称与说明 id：环境数据所属点位的唯一标识符 date：单日观测的时间戳（格式：YYYY-MM-DD） ind_pm25：单日室内细颗粒物（fine particulate matter, PM2.5）浓度，单位为微克每立方米（µg/m³） ind_pm10：单日室内粗颗粒物（PM10）浓度，单位为µg/m³ ind_co：单日室内一氧化碳（carbon monoxide, CO）浓度，单位为百万分比（ppm） ind_co2：单日室内二氧化碳（carbon dioxide, CO2）浓度，单位为ppm ind_temperature：单日室内空气温度，单位为摄氏度（°C） ind_humidity：单日室内相对湿度，单位为百分比（%） ind_pressure：单日室内大气压强，单位为百帕（hPa） out_mean_pm25：周边空气质量监测站测得的单日室外PM2.5平均浓度，单位为µg/m³ out_mean_o3：单日室外臭氧（O3）平均浓度，单位为µg/m³ out_max_o3：单日室外当日臭氧（O3）小时最大浓度，单位为µg/m³