29:null 2a:["$","title",null,{"children":"Air Quality Measurements in Tower Hamlets | Emile Mathieu | Observable"}] 2f:T6aa,# Air Quality Measurements in Tower Hamlets ## Air Quality Measurements (NO₂) in Tower Hamlets before and after Liveable Streets The Liveable Streets schemes have been operational in Tower Hamlets since July 2021. ### What we did We wanted to see if air quality levels have changed following the implementation of one specific area covered by the Liveable Streets road layouts in Bethnal Green. ### How we did it We conducted our analysis using data received from a Freedom of Information request and data provided on the Tower Hamlets Council's [website](https://www.towerhamlets.gov.uk/lgnl/environment_and_waste/environmental_health/pollution/air_quality/Advanced_information_on_air_quality/Monitoring.aspx). This is data collected in monthly intervals using Tower Hamlets' Nitrogen Dioxide Diffusion Tubes. Altogether, the available data starts from May 2015 and runs to December 2024 although for some locations the data only starts at a later date. For our analysis, we compared air quality levels before and after the Liveable Streets scheme in Bethnal Green was installed in the borough. We used the air quality measurements taken from stations inside and bordering the Liveable Streets area, comparing like-for-like 2018-2019 (before) and 2023-2024 (after). *Disclaimer: This analysis was done by volunteers working with the [Save Our Safer Streets campaign](https://heartbg.uk). Where possible, we've sought advice and comment from third parties with relevant experience or expertise. We ask that Tower Hamlets council undertake professional and verified analysis to understand the impacts of the scheme and to determine the borough's needs and how best to serve its communities.*30:T9e3,

Key Results

Tower Hamlets pollution levels have fallen since 2015: Since the Nitrogen Dioxide Diffusion Tube programme began in Tower Hamlets (May 2015), the trend has been a fall in the borough's pollution levels.

Average pollution levels are falling below the national target: From 2020, annual average pollution levels in Tower Hamlets have fallen below the ["National Air Quality Objective"]( https://uk-air.defra.gov.uk/assets/documents/Air_Quality_Objectives_Update.pdf) (i.e. _national target_) of 40 µg/m3 of Nitrogen Dioxide (in-line with [national trends](https://www.gov.uk/government/statistics/air-quality-statistics/ntrogen-dioxide)). Yet the annual average levels are still above the [Word Health Organisation guideline](https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines) of 10 µg/m3.

Pollution levels have also fallen around the Liveable Streets area

Pollution levels have fallen faster inside Liveable Streets than in the rest of the borough: NO₂ concentration have been decreasing at a faster rate and with statistical significance for locations inside the scheme compared to the rest of the borough.

Liveable Streets has _not_ negatively impacted boundary roads: On major artery roads near to scheme NO₂ concentration has _not_ decreased _slower_ than the rest of Tower Hamlets, meaning there is no statistically significant evidence that the scheme has had a negative impact on boundary roads. In one location (Parmiter St/ Cambridge Heath Road), there is statistically significant data showing that the NO₂ levels at have fallen faster than the borough as whole. This is particularly relevant as this location had a high level of pollution to start with.

31:T95f,Plot.plot({ y: { label: "↑ Air quality (NO2 µg/m3)", grid: true, domain: [0, 100] }, x: { type: "time", label: "Month and year →", grid: true, thresholds: d3.utcMonth, tickFormat: d3.utcFormat("%b %y"), tickRotate: 90, line: true, tickPadding: 10 }, marks: [ Plot.lineY(air_quality_not_ltns, { x: "utctimestamp", y: "aq", // sort: null, // stroke: "black", stroke: "location", strokeWidth: 1, opacity: 0.3, filter: (d) => d.aq <= 100, // interval: d3.utcMonth }), // Plot.linearRegressionY(air_quality_not_ltns, // { // x: "utctimestamp", // y: "aq", // // sort: null, // stroke: "location", // strokeWidth: 1, // opacity: .3, // filter: (d) => d.aq !== 0, // interval: d3.utcMonth // }), Plot.lineY(air_quality_not_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "black", strokeWidth: 3, opacity: .5, filter: (d) => d.aq !== 0, interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_not_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "black", strokeWidth: 3, opacity: .5, filter: (d) => d.aq !== 0, interval: d3.utcMonth })), // Plot.lineY(air_quality_ltns, // Plot.binX( // {y: "mean"}, { // x: "utctimestamp", // y: "aq", // sort: null, // stroke: "#71da71", // strokeWidth: 2, // opacity: 0.4, // filter: (d) => d.aq !== 0, // interval: d3.utcMonth // })), // Plot.linearRegressionY(air_quality_ltns, // Plot.binX( // {y: "mean"}, { // x: "utctimestamp", // y: "aq", // sort: null, // fill: "green", // opacity: 0.6, // stroke: "#71da71", // filter: (d) => d.aq !== 0, // interval: d3.utcMonth // })), // National target //Plot.ruleY([40],{stroke: "red", opacity: 0.2, strokeWidth: 3}) ], inset: 10, marginBottom: 85, width: 1240, height: 500 })32:T450,## Average pollution levels fall below the national target In the bar graph, we've plotted the Tower Hamlets NO₂ monthly (thin grey) and yearly (wider grey) averages and both the air quality trend line (dark grey) and national target (brown). We can see lower annual levels from July 2021 that meet the ["National Air Quality Objective"](https://uk-air.defra.gov.uk/assets/documents/Air_Quality_Objectives_Update.pdf) or national target of 40 µg/m3 (in dashed brown), yet are quite higher than the [WHO guideline](https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines) of 10 µg/m3 (in solid brown). There are likely several drivers behind this trend, one, the launch of London's *ultra low emission zone* (ULEZ) in April 2019 along with its extension to all boroughs in August 2023, these leading to less pollution per vehicles. Second there has been an increasing share of electric motorised vehicles, including for taxis, buses, and heavy goods vehicles. Thirdly, there have been tighter controls on pollutions from industrial and heating sources.33:T674,Plot.plot({ color: { type: "categorical", legend: false, scheme: "greys", //legend: "ramp" }, y: { label: "↑ Air quality (NO2 µg/m3)", grid: true, }, x: { type: "time", label: "Month and year →", grid: true, thresholds: d3.utcMonth, tickFormat: d3.utcFormat("%b %y"), tickRotate: 90, line: true, tickPadding: 10 }, marks: [ Plot.rectY(air_quality, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "grey",//d3.mean(air_quality, d => d.aq), opacity: 0.5, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcYear })), Plot.rectY(air_quality, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "grey",//d3.mean(air_quality, d => d.aq), opacity: 0.2, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), Plot.linearRegressionY(air_quality, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "black", strokeWidth: 3, opacity: 0.5, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), // National target Plot.ruleY([40],{stroke: "brown", opacity: 0.5, strokeWidth: 3, strokeDasharray: "4,4"}), Plot.ruleY([10],{stroke: "brown", opacity: 0.5, strokeWidth: 3}) ], inset: 10, marginBottom: 85, width: 640, height: 500 })34:T467,Plot.plot({ x: { //type: "time", label: "Month and year →", grid: true, tickFormat: d3.utcFormat("%b %y") }, y: { label: "↑ Air quality (NO2 µg/m3) at ''" + ltnLocation + "' site", grid: true, domain: [0, 80] }, marks: [ Plot.rectY(air_quality, {x: "utctimestamp", y: "aq", filter: (d) => d.location === ltnLocation && d.period === "before" && d.aq !== 0, interval: d3.utcMonth, curve: "catmull-rom", marker: "circle", fill: d3.schemePastel1[0]}), Plot.rectY(air_quality, {x: "utctimestamp", y: "aq", filter: (d) => d.location === ltnLocation && d.period === "after" && d.aq !== 0, interval: d3.utcMonth, curve: "catmull-rom", marker: "circle", fill: d3.schemePastel1[1]}), Plot.linearRegressionY(air_quality, {x: "utctimestamp", y: "aq", filter: (d) => d.location === ltnLocation && d.aq !== 0, interval: d3.utcMonth, stroke: highlight, opacity: 0.6, strokeWidth: 3}), Plot.ruleY([40],{stroke: "brown", opacity: 0.5, strokeWidth: 3, strokeDasharray: "4,4"}), Plot.ruleY([10],{stroke: "brown", opacity: 0.5, strokeWidth: 3}) ], inset: 10, marginBottom: 45 })35:T2c9e,

	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024
Bethnal Green Rd/ Brick Lane	47.0	45.5	44.3	35.6	36.6	27.4	26.3	26.4	27.7	23.0
Buckfast St/Bethnal Green Rd	42.4	41.8	38.1	35.1	32.5	24.2	22.6	22.3	22.1	17.4
Calvert Ave/Boundary Street	42.1	41.0	39.4	37.1	34.7	26.0	22.0	21.4	20.3	16.0
Colombia Rd/Gossett Street	38.5	37.5	38.4	34.3	32.7	24.9	21.4	20.0	19.6	15.9
Paradise Row/Bethnal Green Rd	49.6	44.1	41.2	41.2	36.0	28.1	28.1	28.4	24.3	20.0
Parmiter St/ Cambridge Heath Road				44.7	40.9	30.3	28.5	27.4	24.9	22.8
Queensbridge Rd/Hackney Rd				55.5	35.3	26.2	24.4	24.4	23.8	20.2
Squirries St/Gosset St				38.4	37.5	27.1	25.4	26.1	22.1	18.2
Warner Place/Hackney Rd	42.0	41.1	40.2	37.9	35.4	25.5	22.5	26.1	25.0	22.2

36:T4eb,

	2018-2019 average	2023-2024 average	Δ (%)	Δ (p-value)	Δ of Δ (p-value)
Inside Liveable Streets	47.2	24.5	↓ 48.1	1.4e-16	0.02
Boundary of Liveable Streets	51.5	29.9	↓ 40.9	2.2e-11	0.18
Rest of Tower Hamlets	49.8	31.6	↓ 36.1	1.6e-12	1.00

37:T5eb, Then using a statistical test known as a _t-test_, we can conclude that _within_ each location there has been statistically significant decrease in No₂ concentration. More crucially we would like to know whether inside the Liveable Streets scheme that decrease has been _faster_ compared to the rest of Tower Hamlets? We answer these by relying on a _difference in differences_ methodology, where we compare the aggregated temporal differences (between the 2023-2024 and 2018-2019 periods) for locations inside the scheme and for the ones bordering it, against the same temporal differences but for the _rest_ of Tower Hamlets locations. Using a _t-test_ on this _difference in differences_ we can conclude that for the three locations inside the scheme the improvement in air has been faster than the rest of Tower Hamlets. Since we get a p-value of 0.02 < 0.05 this is statistically significant. 38:T5b2,Plot.plot({ color: { type: "categorical", scheme: "Pastel1" }, x: { label: "", domain: ["before", "after"], //tickFormat: (d) => d.split("-")[0] }, y: { label: "↑ Average air quality (NO2 µg/m3) for" + " " + selectLocation_3, grid: true, inset: 3, domain: [0, 60], }, marks: [ Plot.text(air_quality_test.filter(d => d.location === selectLocation_3), Plot.groupX( {y: "mean", text:"mean"}, { x: "test_period", dy: 12 })), Plot.ruleY([0]), Plot.ruleY([40],{stroke: "brown", opacity: 0.5, strokeWidth: 3, strokeDasharray: "4,4"}), Plot.ruleY([10],{stroke: "brown", opacity: 0.5, strokeWidth: 3}), Plot.barY(air_quality_test, Plot.groupX( {y: "mean"}, { x: "test_period", y: "aq", sort: null, fill: "grey", fillOpacity: 0.5, filter: d => d.location === "Tower Hamlets" })), Plot.barY(air_quality_test, Plot.groupX( {y: "mean"}, { x: "test_period", y: "aq", sort: null, fill: "period", fillOpacity: .5, filter: d => d.location === selectLocation_3 })), ], marginLeft: 50, // space to the left of the chart marginBottom: 30, // space below the chart insetBottom: 33, // space between the x-axis and the marks insetLeft: 5, marginTop: 20, width: 340 })39:Tc8a,Plot.plot({ height: 90, width: 380, axis: null, marginBottom: 10, marginTop: 10, marginRight: 15, y: { domain: [0, 8] }, x: { domain: [0, 9] }, marks: [ Plot.text([[1, 0]], { x: 2, y: 8, text: ["Before"], lineHeight: 1, fontSize: 12 }), Plot.text([[1, 0]], { x: 5, y: 8, text: ["After"], lineHeight: 1, fontSize: 12 }), Plot.text([[1, 0]], { x: 8, y: 8, text: ["Difference (%)"], lineHeight: 1, fontSize: 12, textAnchor: "middle" }), Plot.text(air_quality, { x: 2, y: 6, text: d => d3.format(".1f")(d3.mean(air_quality.filter(d => d.location === selectLocation_3 && d.test_period === "before"), d => d.aq)), filter: d => d.location === selectLocation_3 && d.test_period === "before", lineHeight: 1, fontSize: 12, monospace: true, fontWeight: "normal", }), Plot.text(air_quality, { x: 5, y: 6, text: d => d3.format(".1f")(d3.mean(air_quality.filter(d => d.location === selectLocation_3 && d.test_period === "after"), d => d.aq)), filter: d => d.location === selectLocation_3 && d.test_period === "after", lineHeight: 1, fontSize: 12, monospace: true, fontWeight: "normal" }), Plot.text(air_quality, { x: 7, y: 6, text: ["↓"], lineHeight: 1, fontSize: 12, textAnchor: "start" }), Plot.text(air_quality, { x: 8, y: 6, // text: d3.mean(air_quality.filter(d => d.aq !== 0 && d.location === selectLocation_3 && d.test_period === "before"), d => d.aq) - d3.mean(air_quality.filter(d => d.aq !== 0 && d.location === selectLocation_3 && d.test_period === "after"), d => d.aq), text: d => d3.format(".1f")((d3.mean(air_quality.filter(d => d.location === selectLocation_3 && d.test_period === "after"), d => d.aq) - d3.mean(air_quality.filter(d => d.location === selectLocation_3 && d.test_period === "before"), d => d.aq))/d3.mean(air_quality.filter(d => d.location === selectLocation_3 && d.test_period === "before"), d => d.aq) * -100), filter: d => d.location === selectLocation_3, lineHeight: 1, fontSize: 12, monospace: true, fontWeight: "normal" }), Plot.text([[1, 0]], { x: 1, y: 0, text: ["P-Value:"], fontStyle: "italic", lineHeight: 1, fontSize: 12, textAnchor: "start" }), Plot.text( air_quality_test, { x: 3, y: 0, // text: d => d["t-test"], text: d => d3.format(".2e")(d["t-test"]), // filter: d => d.location === selectLocation_3 && d["t-test"] !== null, filter: d => d.location === selectLocation_3, fontSize: 13, lineHeight: 1, monospace: true, fontWeight: "bold", textAnchor: "start" } ), Plot.text( ["Probability of no change between periods."], { x: 1, y: 2, //frameAnchor: "start", fontSize: 12, lineWidth: 32, textAnchor: "start", lineHeight: 1, //monospace: true, }), ], })3a:Ta15,## Liveable Streets have not negatively impacted boundary roads We also wanted to check whether Liveable Streets have been impacting air quality on the busier main roads that are on the boundary of the scheme. To do this, we looked at the declines in NO₂ levels on boundary roads (i.e. Hackney Road, Bethnal Green Road and Cambridge Heath Road). In the table below, as in the previous section we compute a _t-test_ estimator on the difference between the NO₂ change for each measurement station located at the boundary of Liveable Streets, compared to the rest of Tower Hamlets. Although the data would seem to suggest that the air quality has been improving faster in most parts of the boundary roads than elsewhere in the borough, in fact, for the boundary roads overall and most individual location on the boundary, we cannot draw definitive conclusions as the results of the calculations are not statistically significant. This is shown by the fact that the p-value is greater than 0.05. One location did yield a statistically significant result. The station at the junction between Parmiter St/ Cambridge Heath Road has been showing NO₂ levels decreasing at a _faster_ rate than the rest of the borough, since the p-value of the t-test over the difference of differences is 0.0053 this finding is statistically significantly. This station is located near the busy junction of Hackney Rd and Cambridge Heath, and as such the aveerage NO₂ concentration over 2018-2019 was of 56.5 µg/m3 which is much higher than the rest of the borough average of 49.8 µg/m3. After the scheme was installed, both the Parmiter St/ Cambridge Heath Rd location produced identical average readings to the borough average of ~31 µg/m3. While we cannot be entirely sure of the reasons for this, it could be explained by the massive reduction in traffic on the Old Bethnal Green Rd area. 3b:Tc92,

	2018-2019 average	2023-2024 average	Change (%)	Δ of Δ	p-value
Inside Liveable Streets	47.2	24.5	↓ 48.1	-2.4	0.020
Colombia Rd/Gossett Street	44.4	23.3	↓ 47.6	-1.7	0.103
Calvert Ave/Boundary Street	47.6	23.9	↓ 49.9	-3.0	0.005
Squirries St/Gosset St	50.3	26.5	↓ 47.3	-2.6	0.014
Boundary of Liveable Streets	51.5	29.9	↓ 42.0	-1.4	0.183
Paradise Row/Bethnal Green Rd	51.1	29.5	↓ 42.3	-1.3	0.186
Parmiter St/ Cambridge Heath Road	56.5	31.3	↓ 44.5	-2.9	0.005
Warner Place/Hackney Rd	48.6	31.1	↓ 36.0	0.3	0.742
Queensbridge Rd/Hackney Rd	58.8	28.9	↓ 50.9	-1.5	0.153
Bethnal Green Rd/ Brick Lane	47.9	33.5	↓ 30.0	1.4	0.175
Buckfast St/Bethnal Green Rd	44.7	25.7	↓ 42.5	-0.6	0.527
Rest of Tower Hamlets	49.8	31.6	↓ 36.6	0.0	1.000

3c:T72b,The Government's ["National Air Quality Objective"]( https://uk-air.defra.gov.uk/assets/documents/Air_Quality_Objectives_Update.pdf) (or what we are calling the *national target*) is used to evaluate annual air quality measures, recognising there is likely to be variation over the year. Evidence of the relationship between annual average NO₂ and short term peak NO₂ shows that where annual average is below 60µg/m3, the hourly (1 hour mean) NO₂ air quality objective (‘200 µg/m3 not to be exceeded more than 18 times a year’) is unlikely to be exceeded (see this [DEFRA report](https://laqm.defra.gov.uk/documents/NO2relationship_report.pdf)). As none of the monitored sites in and around the Tower Hamlets Liveable Streets come close to an annual mean of 60µg/m3, it is safe to discount any significant risk of these sites exceeding the 1 hour mean short term air quality objective to protect acute health risks. We note though that the NO₂ are still too high to meet the [World Health Organisation (WHO) guidelines](https://www.who.int/news-room/feature-stories/detail/what-are-the-who-air-quality-guidelines) which recommend a maximum annual average concentration of 10 µg/m3 for NO₂. There is no part of Tower Hamlets, including the Bethnal Green Liveable Streets area, which is consistently below this level. What's more, air pollution is assessed by more than NO₂ concentration and typically include air pollutants concentration measurements such as PM2.5 and PM10 (particles with an aerodynamic diameter of equal or less than 2.5, also called fine, and 10 micrometre respectively), ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO) and sulfur dioxide (SO2). Due to the lack of available data for these we did not investigate their variations.3d:T6a4,Plot.plot({ y: { label: "↑ Air quality (NO2 µg/m3)", grid: true }, x: { type: "time", label: "Month and year →", grid: true, thresholds: d3.utcMonth, tickFormat: d3.utcFormat("%b %y"), tickRotate: 90, line: true, tickPadding: 10 }, marks: [ Plot.lineY(air_quality_not_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "black", strokeWidth: 1, opacity: 0.3, filter: (d) => d.aq !== 0, interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_not_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "black", strokeWidth: 1, opacity: 0.3, filter: (d) => d.aq !== 0, interval: d3.utcMonth })), Plot.lineY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "#71da71", strokeWidth: 2, opacity: 0.4, filter: (d) => d.aq !== 0, interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "green", opacity: 0.6, stroke: "#71da71", filter: (d) => d.aq !== 0, interval: d3.utcMonth })), // National target //Plot.ruleY([40],{stroke: "red", opacity: 0.2, strokeWidth: 3}) ], inset: 10, marginBottom: 85, width: 1240, height: 500 })3e:T624,Plot.plot({ color: { type: "categorical", legend: false, scheme: "greys", //legend: "ramp" }, y: { label: "↑ Air quality (NO2 µg/m3)", grid: true }, x: { type: "time", label: "Month and year →", grid: true, thresholds: d3.utcMonth, tickFormat: d3.utcFormat("%b %y"), tickRotate: 90, line: true, tickPadding: 10 }, marks: [ Plot.rectY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "green",//d3.mean(air_quality, d => d.aq), opacity: 0.4, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcYear })), Plot.rectY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "green",//d3.mean(air_quality, d => d.aq), opacity: 0.2, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "green", strokeWidth: 1, opacity: 0.9, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), // National target Plot.ruleY([40],{stroke: "red", opacity: 0.2, strokeWidth: 3}) ], inset: 10, marginBottom: 85, width: 640, height: 500 })3f:Ta48,Plot.plot({ color: { type: "categorical", legend: false, scheme: "greys", //legend: "ramp" }, y: { label: "↑ Air quality (NO2 µg/m3)", grid: true }, x: { type: "time", label: "Month and year →", grid: true, thresholds: d3.utcMonth, tickFormat: d3.utcFormat("%b %y"), tickRotate: 90, line: true, tickPadding: 10 }, marks: [ // Plot.rectY(air_quality, // Plot.binX( // {y: "mean"}, { // x: "utctimestamp", // y: "aq", // sort: null, // fill: "grey",//d3.mean(air_quality, d => d.aq), // opacity: 0.2, // filter: (d) => d.aq !== 0 && !d.month.includes("-15"), // interval: d3.utcYear // })), Plot.rectY(air_quality, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "grey",//d3.mean(air_quality, d => d.aq), opacity: 0.2, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), Plot.linearRegressionY(air_quality, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "#666666", strokeWidth: 1, opacity: 0.9, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), // Plot.rectY(air_quality_ltns, // Plot.binX( // {y: "mean"}, { // x: "utctimestamp", // y: "aq", // sort: null, // fill: "green",//d3.mean(air_quality, d => d.aq), // opacity: 0.2, // filter: (d) => d.aq !== 0 && !d.month.includes("-15"), // interval: d3.utcYear // })), Plot.rectY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "green",//d3.mean(air_quality, d => d.aq), opacity: 0.2, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, stroke: "green", strokeWidth: 1, opacity: 0.9, filter: (d) => d.aq !== 0 && !d.month.includes("-15"), interval: d3.utcMonth })), // National target Plot.ruleY([40],{stroke: "red", opacity: 0.2, strokeWidth: 3}) ], inset: 10, marginBottom: 85, width: 640, height: 500 })40:T4ea,Plot.plot({ color: { //type: "categorical", legend: false, scheme: "rdylgn", type: "diverging-symlog", pivot: 30, symmetric: true, reverse: true, //legend: "ramp" }, y: { label: "Air quality (NO2 µg/m3) for all LTN areas", grid: true }, x: { type: "time", label: "Month and year →", //grid: true, //thresholds: d3.utcMonth, tickFormat: d3.utcFormat("20%y") }, marks: [ Plot.rectY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "#9ce085", filter: (d) => d.aq !== 0, interval: d3.utcMonth })), Plot.linearRegressionY(air_quality_ltns, Plot.binX( {y: "mean"}, { x: "utctimestamp", y: "aq", sort: null, fill: "green", stroke: "green", filter: (d) => d.aq !== 0, interval: d3.utcMonth })), //Plot.linearRegressionY(air_quality, {x: "utctimestamp", y: "aq", filter: (d) => d.aq !== 0, interval: d3.utcMonth, fill: "aq", opacity: 0.6}), //Plot.ruleY([40],{stroke: "red", opacity: 0.2, strokeWidth: 3}) ], inset: 10, marginBottom: 45, width: 800 })41:T8ee,

	2015	2016	2017	2018	2019	2020	2021
Bethnal Green Rd/ Brick Lane	46.98	45.54	44.28	35.64	36.58	27.40	26.33
Calvert Ave/Boundary Street	42.10	40.98	39.43	37.15	34.66	26.00	21.96
Colombia Rd/Gossett Street	38.46	37.48	38.37	34.30	32.74	24.90	21.45
Grove Rd/Old Ford Rd	47.05	47.78	45.12	42.53	40.49	27.50	26.83
Paradise Row/Bethnal Green Rd	49.64	44.07	41.17	41.18	36.01	28.10	28.07
Parmiter St/ Cambridge Heath Road				44.74	40.87	30.30	28.53
Queensbridge Rd/Hackney Rd				55.45	35.26	26.20	24.41
Roman Rd/Globe Road				36.21	34.13	25.80	26.82
Squirries St/Gosset St				38.35	37.55	27.10	25.43
Warner Place/Hackney Rd	42.01	41.15	40.19	37.94	35.44	25.50	22.54
Whitechapel High Street	72.24	63.55	61.51	61.16	47.84	33.90	37.70

42:T8ff,locations = ["Ackroyd Drive", "Admirals Way", "Augusta St/Giraud St", "Ben Johnson Road", "Bethnal Green Rd/ Brick Lane", "Blair Street (End of Street)", "Bonner Road", "Bow Common Lane/St Paul's Way", "Bow Rd /Glebe Terrace", "Bow Rd/Alfred St", "Brick Lane/Princelet St", "Brodlove Lane", "Bromley High Street/ St Leonards", "Buckfast St/Bethnal Green Rd", "Calvert Ave/Boundary Street", "Cartwright Street", "Cascades, Westferry Road", "Cavell St/Stepney Way", "Chrisp Street/E India Dock Road ", "Columbia Rd/Gossett Street", "Commercial St/Calvin St", "Dellow St/The Highway", "Devas Street /Devons road", "Devons Road / Campbell Road ", "Dod St/Burdett Rd", "Dolphin Lane", "Fairfield Road/Tredegar Road ", "Fieldgate Street", "Finnis St/Three Colts Lane", "Ford Close/Roman Rd", "Globe Rd/Mile End Rd", "Grove Rd/Old Ford Rd", "Hale Street", "Hannibal Rd/Mile End Rd", "Harford St/Mile End Rd", "Hatfield Terrace/Fairfield Road", "John Smith Mews", "Jubilee Street/Commercial Rd", "Lawnhouse Close ", "Limeharbour", "Locksley St/St Paul's Way", "Manchester Road/East Ferry Road", "Manchester Road/Ollife Street ", "Mansell St", "Mast House Terrace", "Mile End Road Corner Bancroft Rd", "Millwall Park 1", "Millwall Park 2", "Morris/Barchester Street", "Narrow St/Limehouse Link", "Newport Avenue", "Paradise Row/Bethnal Green Rd", "Parmiter St/ Cambridge Heath Road", "Parnell Rd/Old Ford Rd", "Philpot St/Commercial Road", "Pitsea St/Commercial Rd", "Poplar High St/Cotton St", "Portree Street", "Prestons Road/ Coldharbour", "Queensbridge Rd/Hackney Rd", "Rhodeswell Rd", "Rhondda Grove/Mile End Rd", "Rich Street", "Roman Rd/Globe Road", "Sextant Avenue", "Seyssel Street", "Shirbutt St o/s Holy Family School", "Sidney St/Mile End Rd", "Squirries St/Gosset St", "St Katherine's Way", "St Stephen's Rd/Tredegar Rd", "Stepney Green", "TH Cemetery Park", "Thames Path Storers Quay", "Thoydon Rd", "Toynbee St/Commercial St", "Victoria Park (Co-location site 1)", "Victoria Park (Co-location site 2)", "Wapping High St/Sampson St", "Wapping Wall/Garnet St", "Warner Place/Hackney Rd", "Watney Market", "Wentworth Mews", "Westferry Road/Limehouse Link jnct", "Whitechapel High St (KFC)", "Whitechapel Market", "Whitechapel Rd/Adler St", "Wick Lane/Autumn St", "Wrexham Road", "Zetland Street/A12"]43:[{"id":"c361fa883f01c899854ec2bd1c4a0ce1c85490ea6fd147f4e0cf862f2c5fc590369004d5f206727ea66cd366211d0dd7c201db038c217e06ab2bf31774a84681","href":"https://static.observableusercontent.com/files/c361fa883f01c899854ec2bd1c4a0ce1c85490ea6fd147f4e0cf862f2c5fc590369004d5f206727ea66cd366211d0dd7c201db038c217e06ab2bf31774a84681","name":"air_quality_v4_test@5.csv","type":"text/csv","lastModified":1747582534029.673,"size":530647},{"id":"e3766ec6c935df8dad326f13ac5c1a8ee0d9784d660311bc9f476676cb0c05ae8eae3d31011714633ec038b4256fbbb0ca4e5d9298fed7e602321a5fe49c6f05","href":"https://static.observableusercontent.com/files/e3766ec6c935df8dad326f13ac5c1a8ee0d9784d660311bc9f476676cb0c05ae8eae3d31011714633ec038b4256fbbb0ca4e5d9298fed7e602321a5fe49c6f05","name":"N02_locations.jpg","type":"image/jpeg","lastModified":1747764627828.863,"size":1609877},{"id":"e44c9730cf71c80d991fa0c1ba73d659fe2441e818b669f485801a455c779d081731228a045b7f3cf4de87e7b7204528b87e49838bc5c9b903e9004bc001253a","href":"https://static.observableusercontent.com/files/e44c9730cf71c80d991fa0c1ba73d659fe2441e818b669f485801a455c779d081731228a045b7f3cf4de87e7b7204528b87e49838bc5c9b903e9004bc001253a","name":"N02_locations@1.jpg","type":"image/jpeg","lastModified":1747765115974.958,"size":358169},{"id":"f06beb77b580ff7ad398dbf9e5687e09579f1f6216b68df20a96b916fac1699468687dfb98c3973ee3cac22ec3dffe8ce29adfd517d986306474bfdb56c92bab","href":"https://static.observableusercontent.com/files/f06beb77b580ff7ad398dbf9e5687e09579f1f6216b68df20a96b916fac1699468687dfb98c3973ee3cac22ec3dffe8ce29adfd517d986306474bfdb56c92bab","name":"air_quality_v4@3.csv","type":"text/csv","lastModified":1747258608084.858,"size":685276}] 2d:{"id":"643975da29b9b5d4","slug":"air-quality-measurements-in-tower-hamlets","title":"Air Quality Measurements in Tower Hamlets","thumbnail":"f1aacd6857a4aa0dc381642ebeb9d5e80c3ea5ce56105ade560d57cb76d82677","access_level":"public","create_time":"$D2025-04-13T16:32:52.786Z","update_time":"$D2025-05-20T18:36:25.683Z","view_time":null,"first_public_time":"$D2025-04-13T16:32:52.786Z","has_unpublished_edits":null,"fork":{"id":"a6160198e9d9a000","slug":"air-quality-measurements-in-tower-hamlets","title":"Air Quality Measurements in Tower Hamlets","owner":{"id":"b2e8b22fd64f7967","login":"soss","name":"Save our Safer Streets"}},"stars":0,"starred":false,"owner":{"type":"team","id":"d8d4735a38ee536e","login":"emile-mathieu","name":"Emile Mathieu","avatar_url":"https://avatars-next.observableusercontent.com/35ffe7a03ed5ec3496d971ae25cee385b584b5c27f1ca97b5fde0152339cd71a","tier":"starter_2024"},"version":2578,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"fcfd6e2483c61df2","login":"emile-mathieu","name":"Emile Mathieu","avatar_url":"https://avatars-next.observableusercontent.com/fdaef8cca9f4b97113845f3dff9333b3fb28cd25f2115478976d180788ff3ade","tier":null}],"members":[{"type":"team","id":"d8d4735a38ee536e","login":"emile-mathieu","name":"Emile Mathieu","avatar_url":"https://avatars-next.observableusercontent.com/35ffe7a03ed5ec3496d971ae25cee385b584b5c27f1ca97b5fde0152339cd71a","tier":"starter_2024","role":"editor"},{"type":"individual","id":"fcfd6e2483c61df2","login":"emile-mathieu","name":"Emile Mathieu","avatar_url":"https://avatars-next.observableusercontent.com/fdaef8cca9f4b97113845f3dff9333b3fb28cd25f2115478976d180788ff3ade","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"title":"Air Quality Measurements in Tower Hamlets","cells":[{"id":0,"value":"$2f","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":647,"value":"$30","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":623,"value":"## Tower Hamlets Pollution levels have fallen since 2015\n\nFirst we look at the overall air quality variation across the last decade in Tower Hamlets as a whole. \n\n\nBelow, we've plotted the average monthly NO₂ levels for each measurement station in Tower Hamlets (in rainbow colours) and the aggregated mean (grey line).\n\nWe additionally included the linear aggregated trend in grey.\n\nFrom the trend line, we see that NO₂ levels of all locations have been decreasing since the measurements started in 2015.\n\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":846,"value":"Plot.legend({\n color: {\n type: \"categorical\",\n domain: [\"Tower Hamlets\"], \n range: [\"gray\"]\n }\n})\n// Plot.legend({\n// color: {\n// type: \"categorical\",\n// domain: [\"Tower Hamlets\", \"LTN areas\"], \n// range: [\"gray\", \"#71da71\"]\n// }\n// })","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":677,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":911,"value":"$32","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":952,"value":"Plot.legend({\n color: {\n type: \"categorical\",\n domain: [\"National target\", \"Air quality monthly average\", \"Trend for Tower Hamlets\"], \n range: [\"brown\", \"grey\", \"#666666\"]\n }\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":893,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":949,"value":"> *In the graphs above:*\n - *NO₂ measures for 2015 have been omitted as they only begin in May;*\n - *Where there are missing bars, no data has been collected — in particular, no data was collected during the first Covid lockdown, starting March 2020.*\n\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":627,"value":"## Pollution levels are falling in the areas near to the scheme\n\nWe now look at the NO₂ measurements from diffusion tubes at locations near to the Bethnal Green Liveable Streets scheme.\nThese can be split in the ones located inside the scheme:\n- Colombia Rd/Gossett Street\n- Calvert Ave/Boundary Street\n- Squirries St/Gosset St\n\nand these ones located at the boundary:\n- Paradise Row/Bethnal Green Rd\n- Parmiter St/ Cambridge Heath Road\n- Warner Place/Hackney Rd\n- Queensbridge Rd/Hackney Rd\n- Bethnal Green Rd/ Brick Lane\n- Buckfast St/Bethnal Green Rd","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2567,"value":"image = FileAttachment(\"N02_locations@1.jpg\").image()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2570,"value":"\nThe graph below shows that in all of these locations the trend is a fall in pollution (NO₂) levels.\n\n> *Choose a location below to see the downward (NO₂) trends in each location within or near the scheme.*","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":190,"value":"viewof ltnLocation = Inputs.select(ltn_locations, {label: \"Choose location\", value: \"Squirries St/Gosset St\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":41,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":216,"value":"> *Above, the pink bars represent measurements taken before the Liveable Streets were installed and the blue bars after. The green line is the trend for measurements between May 2015 and runs to December 2024. Please note some locations only have data from 2018.\n\n*","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2157,"value":"If we look at the yearly NO₂ averages, we see these downward trends in pollution confirmed. In Table 1, the bias-adjusted annual averages in each location fall below the national target of 40 µg/m3 by 2020 (for further information about adjusting for bias see this [helpful webpage](https://lovecleanair.org/about-air-quality/how-pollutants-measured/co-location-sites-bias-adjustment/)). Although note that none fall below the WHO guideline of 10 µg/m3.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":299,"value":"$35","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":306,"value":"Plot.plot({\n height: 74,\n marginBottom: 6,\n marginTop: 5,\n marks: [\n Plot.text(\n [\"Table 1. Bias adjusted and annualised average monthly NO2 levels between 2015 to 2024 for locations near Bethnal Green Liveable Streets. We've followed the guidance accompanying the Tower Hamlets dataset, and reduced the 2024 values by 25%. 2015 values are estimated from May-December data.\"],\n {\n frameAnchor: \"top\",\n fontSize: 12,\n lineWidth: 52,\n //textAnchor: \"start\",\n lineHeight: 1.3,\n // monospace: true,\n //clip: true\n }\n ),\n // Plot.text(\n // [\"* 2022 values are calculated using monthly values to July 2022 and August to December figures from 2021.\"],\n // {\n // frameAnchor: \"bottom\",\n // fontSize: 12,\n // lineWidth: 38,\n // //textAnchor: \"start\",\n // lineHeight: 1.3,\n // // monospace: true,\n // //clip: true\n // }\n // )\n ],\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1394,"value":"In sum, air quality levels have improved in all areas surrounding the Bethnal Green Liveable Streets area.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1210,"value":"## Pollution levels have fallen faster inside the Liveable Streets area\n\nTo look at the possible impact Bethnal Green’s Liveable Streets scheme has had on air quality, we compared like-for-like periods before and after they were installed. We've based our analysis on Liveable Streets being operational from 1st July 2021 (though some of the new road layouts were being modified well after this date). We thus chose to compare the 2018-2019 and 2023-2024 periods.\n\n\nIn the table below, we aggregated the No₂ measures for all locations inside the Liveable Streets and similarly for the bordering locations. As a _control_ variable we did the same for all other locations in Tower Hamlets.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1045,"value":"$36","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2235,"value":"$37","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1231,"value":"\n\n\n\n> *To see comparisons between the before and after periods for the individual locations near the Liveable Streets and for Tower Hamlets, choose from the \"*Choose location*\" option below.*","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":352,"value":"viewof selectLocation_3 = Inputs.select(ltn_locations_and_TH, {label: \"Choose location\", value: \"Paradise Row/Bethnal Green Rd\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1930,"value":"$38","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2516,"value":"Plot.plot({\n marginBottom: 6,\n marginTop: 5,\n // width: 400,\n marks: [\n Plot.text(\n [\"The blue and red bars respectively show the average NO2 concentration on the 2018-2019 period (aka before) and 2023-2014 period (after). The grey bars represent the NO2 concentration averaged across the rest of the borough.\"],\n {\n frameAnchor: \"top\",\n fontSize: 12,\n lineWidth: 52,\n // textAnchor: \"start\",\n lineHeight: 1.3,\n // monospace: true,\n //clip: true\n }\n ),\n ],\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1983,"value":"$39","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2245,"value":"Plot.plot({\n height: 90,\n width: 380,\n axis: null,\n marginBottom: 10,\n marginTop: 10,\n marginRight: 15,\n y: {\n domain: [0, 8]\n },\n x: {\n domain: [0, 9]\n },\n marks: [\n Plot.text([[1, 0]], {\n x: 1,\n y: 0,\n text: [\"P-Value:\"],\n fontStyle: \"italic\",\n lineHeight: 1,\n fontSize: 12,\n textAnchor: \"start\",\n }),\n Plot.text(\n air_quality_test,\n {\n x: 3,\n y: 0,\n text: d => d[\"t-test wrt TH\"],\n filter: d => d.location === selectLocation_3,\n fontSize: 13,\n lineHeight: 1,\n monospace: true,\n fontWeight: \"bold\",\n textAnchor: \"start\"\n }\n ),\n Plot.text(\n [\"Probability of no difference vs Tower Hamlets.\"],\n {\n x: 1,\n y: 2,\n //frameAnchor: \"start\",\n fontSize: 12,\n lineWidth: 32,\n textAnchor: \"start\",\n lineHeight: 1,\n //monospace: true,\n }),\n ],\n \n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1227,"value":"$3a","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1422,"value":"Plot.plot({\n height: 40,\n marginBottom: 6,\n marginTop: 5,\n marks: [\n Plot.text(\n [\"Table 3. Before and after comparisons for main artery roads near Livable Streets, and for Tower Hamlets as a whole.\"],\n {\n frameAnchor: \"top\",\n fontSize: 12,\n lineWidth: 38,\n //textAnchor: \"start\",\n lineHeight: 1.3,\n // monospace: true,\n //clip: true\n }\n )\n ],\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1957,"value":"$3b","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2387,"value":"## Notes","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1090,"value":"$3c","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1697,"value":"## See more analysis\n\n- [Ambulance response times](https://i.heartbg.uk/LAS-response-time-analysis)\n- [Fire service response times](https://i.heartbg.uk/LFB-response-time-analysis)","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":8,"value":"## Appendix","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":222,"value":"","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":2344,"value":"$3d","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":955,"value":"Plot.legend({\n color: {\n type: \"categorical\",\n domain: [\"National target\", \"Air quality monthly average\", \"Trend for LTN areas\"], \n range: [\"red\", \"#71da71\", \"green\"]\n }\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":945,"value":"$3e","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1915,"value":"Plot.legend({\n color: {\n type: \"categorical\",\n domain: [\"National target\", \"Tower Hamlets\", \"LTN areas\"], \n range: [\"red\", \"grey\", \"green\"]\n }\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1900,"value":"$3f","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":715,"value":"$40","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":861,"value":"Above, the darker bars indicate higher levels of pollution. The horizontal red bar is the nation target (40 µg/m3 Nitrogen Dioxide). Where no data has been collected there are missing bars — for example no data was collected during the first Covid lockdown, starting March 2020.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":103,"value":"viewof location = Inputs.select(locations, {label: \"Choose location\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":879,"value":"Plot.legend({\n color: {\n type: \"categorical\",\n domain: [\"National target\", \"Monthly air quality level\", \"Trend for LTN area\"], \n range: [\"red\", \"grey\", \"#71da71\"]\n }\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"Plot.plot({\n color: {\n type: \"categorical\",\n nice: true,\n legend: false,\n scheme: \"greys\",\n //reverse: true,\n },\n y: {\n label: \"↑ Air quality (NO2 µg/m3) on \" + location,\n grid: true\n },\n x: {\n type: \"time\",\n label: \"Month and year →\",\n grid: true,\n thresholds: d3.utcMonth,\n tickFormat: d3.utcFormat(\"%b %y\")\n },\n marks: [\n Plot.rectY(air_quality, {x: \"utctimestamp\", y: \"aq\", filter: (d) => d.location === location && d.aq !== 0, interval: d3.utcMonth, fill: \"aq\"}),\n Plot.linearRegressionY(air_quality, {x: \"utctimestamp\", y: \"aq\", filter: (d) => d.location === location && d.aq !== 0, interval: d3.utcMonth, stroke: \"green\", opacity: 0.6}),\n Plot.ruleY([40],{stroke: \"red\", opacity: 0.2, strokeWidth: 3})\n ],\n inset: 10,\n marginBottom: 45,\n width: 800\n}\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":239,"value":"$41","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":141,"value":"operationalDate = new Date('2021-07-01') // Assumed date LTNs installed","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":985,"value":"TH_mean = d3.mean(air_quality.filter(d => d.aq !== 0), d => d.aq).toFixed(2)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1009,"value":"ltn_mean_before_period = d3.mean(air_quality_ltns.filter(d => d.test_period === \"before\" && d.aq !== 0), d => d.aq)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1015,"value":"ltn_mean_after_period = d3.mean(air_quality_ltns.filter(d => d.test_period === \"after\" && d.aq !== 0), d => d.aq)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1043,"value":"ltn_change = ltn_mean_before_period - ltn_mean_after_period","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":988,"value":"not_ltn_mean = d3.mean(air_quality_not_ltns.filter(d => d.aq !== 0), d => d.aq)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1018,"value":"not_ltn_mean_before_period = d3.mean(air_quality_not_ltns.filter(d => d.test_period === \"before\" && d.aq !== 0), d => d.aq)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1023,"value":"not_ltn_mean_after_period = d3.mean(air_quality_not_ltns.filter(d => d.test_period === \"after\" && d.aq !== 0), d => d.aq)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1041,"value":"not_ltn_change = not_ltn_mean_before_period - not_ltn_mean_after_period","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2083,"value":"air_quality_test = FileAttachment(\"air_quality_v4_test@5.csv\").csv({typed: true})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":10,"value":"air_quality = FileAttachment(\"air_quality_v4@3.csv\").csv({typed: true})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":706,"value":"air_quality_ltns = air_quality.filter(d => ltn_locations.includes(d.location))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":765,"value":"air_quality_not_ltns = air_quality.filter(d => !ltn_locations.includes(d.location))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":99,"value":"function highlight(d) {\n var color = \"green\"\n return color;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":119,"value":"$42","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2138,"value":"inside_ltn_locations = [\n \"Colombia Rd/Gossett Street\",\n \"Calvert Ave/Boundary Street\",\n \"Squirries St/Gosset St\",\n ]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":2141,"value":"boundary_ltn_locations = [\n \"Paradise Row/Bethnal Green Rd\",\n \"Parmiter St/ Cambridge Heath Road\",\n \"Warner Place/Hackney Rd\",\n \"Queensbridge Rd/Hackney Rd\",\n \"Bethnal Green Rd/ Brick Lane\",\n \"Buckfast St/Bethnal Green Rd\",\n ]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":174,"value":"ltn_locations = [...inside_ltn_locations, ...boundary_ltn_locations]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":1257,"value":"ltn_locations_and_TH = [...ltn_locations, \"Tower Hamlets\"]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W43","stdlib":"1","titling":"auto"}} 2e:"$2d:body"