Municipal Wastewater COVID19 Sampling Data 10/1/2020-6/30/2022

This dataset is no longer being updated as of 6/30/2022. It is being retained on the Open Data Portal for its potential historical interest.

In November 2020, the City of Cambridge began collecting and analyzing COVID-19 data from municipal wastewater, which can serve as an early indicator of increased COVID-19 infections in the city. The Cambridge Public Health Department and Cambridge Department of Public Works are using technology developed by Biobot, a Cambridge based company, and partnering with the Massachusetts Water Resources Authority (MWRA). This Cambridge wastewater surveillance initiative is funded through a $175,000 appropriation from the Cambridge City Council.

This dataset indicates the presence of the COVID-19 virus (measured as viral RNA particles from the novel coronavirus per ml) in municipal wastewater. The Cambridge site data here were collected as a 24-hour composite sample, which is taken weekly. The MWRA site data ere were collected as a 24-hour composite sample, which is taken daily. MWRA and Cambridge data are listed here in a single table.

An interactive graph of this data is available here: https://cityofcambridge.shinyapps.io/COVID19/?tab=wastewater

All areas within the City of Cambridge are captured across four separate catchment areas (or sewersheds) as indicated on the map viewable here: https://cityofcambridge.shinyapps.io/COVID19/_w_484790f7/BioBot_Sites.png. The North and West Cambridge sample also includes nearly all of Belmont and very small areas of Arlington and Somerville (light yellow). The remaining collection sites are entirely -- or almost entirely -- drawn from Cambridge households and workplaces.

Data are corrected for wastewater flow rate, which adjusts for population in general. Data listed are expected to reflect the burden of COVID-19 infections within each of the four sewersheds. A lag of approximately 4-7 days will occur before new transmissions captured in wastewater data would result in a positive PCR test for COVID-19, the most common testing method used. While this wastewater surveillance tool can provide an early indication of major changes in transmission within the community, it remains an emerging technology. In assessing community transmission, wastewater surveillance data should only be considered in conjunction with other clinical measures, such as current infection rates and test positivity.

Each location is selected because it reflects input from a distinct catchment area (or sewershed) as identified on the color-coded map. Viral data collected from small catchment areas like these four Cambridge sites are more variable than data collected from central collection points (e.g., the MWRA facility on Deer Island) where wastewater from dozens of communities are joined and mixed. Data from each catchment area will be impacted by daily activity among individuals living in that area (e.g., working from home vs. traveling to work) and by daytime activities that are not from residences (businesses, schools, etc.) As such, the Regional MWRA data provides a more stable measure of regional viral counts. COVID wastewater data for Boston North and Boston South regions is available at https://www.mwra.com/biobot/biobotdata.htm

本数据集自2022年6月30日起停止更新，现留存于开放数据门户（Open Data Portal）以供潜在的历史研究参考。

2020年11月，剑桥市启动市政污水新冠病毒（COVID-19）数据的采集与分析工作，此类数据可作为本市新冠感染人数上升的早期预警指标。剑桥市公共卫生部与公共工程局采用了剑桥本地企业Biobot开发的技术，并与马萨诸塞州水资源管理局（Massachusetts Water Resources Authority, MWRA）开展合作。本剑桥市污水监测项目由剑桥市议会拨款17.5万美元资助。

本数据集记录了市政污水中新冠病毒的检出情况（检测指标为每毫升污水中新型冠状病毒（novel coronavirus）的病毒RNA颗粒数）。本次公开的剑桥市采样点数据为每周采集的24小时混合样本；MWRA采样点数据为每日采集的24小时混合样本。MWRA与剑桥市的监测数据汇总于同一张数据表中。

本数据集的交互式可视化图表可通过以下链接获取：https://cityofcambridge.shinyapps.io/COVID19/?tab=wastewater

剑桥市全境的监测覆盖四个独立的汇水区（sewersheds，污水汇水区），具体分布可查看以下链接中的地图：https://cityofcambridge.shinyapps.io/COVID19/_w_484790f7/BioBot_Sites.png。剑桥市北片区与西片区的采样样本还覆盖了贝尔蒙特市的全部区域，以及阿灵顿与萨默维尔市的极小部分区域（浅黄色标注区域）。其余采样点的样本则全部或几乎全部取自剑桥市的住宅与工作场所。

本数据集已针对污水流量进行校正，以适配整体人口规模变化。公开的数据旨在反映四个污水汇水区内的新冠感染负担。污水监测数据捕捉到的病毒传播情况，相较于当前主流检测手段——新冠聚合酶链式反应（PCR）检测——的阳性结果，存在约4至7天的滞后性。尽管此类污水监测工具可提前预警社区传播的重大变化，但该技术仍处于发展初期。在评估社区传播情况时，污水监测数据仅应与当前感染率、检测阳性率等临床监测指标结合参考。

每个采样点均对应彩色编码地图中标注的独立汇水区。相较于集中采样点（例如鹿岛MWRA监测设施，该设施汇集并混合了数十个社区的污水）采集的数据，剑桥市这四个小型汇水区的病毒监测数据波动性更强。每个汇水区的监测数据会受到当地居民日常活动（如居家办公与通勤）以及非居住场所（企业、学校等）日间活动的影响。因此，MWRA的区域监测数据能够更稳定地反映区域病毒载量。波士顿北片区与南片区的新冠污水监测数据可通过以下链接获取：https://www.mwra.com/biobot/biobotdata.htm