{"id":17469,"date":"2021-06-29T01:29:13","date_gmt":"2021-06-28T17:29:13","guid":{"rendered":"https:\/\/smartairfilters.com\/?p=17469"},"modified":"2021-07-07T09:07:43","modified_gmt":"2021-07-07T01:07:43","slug":"when-exercise-in-delhi-pollution-becomes-harmful","status":"publish","type":"post","link":"https:\/\/smartairfilters.com\/en\/blog\/when-exercise-in-delhi-pollution-becomes-harmful\/","title":{"rendered":"At What Point Is Exercise in Delhi Pollution Harmful?"},"content":{"rendered":"

Air pollution is one of the biggest killers in Delhi. So, it would make sense to wonder whether exercising on a polluted day in Delhi does more harm than good. <\/p>\n\n\n\n

Below is a picture of people exercising in Delhi with PM2.5 air pollution levels at 150 micrograms or an AQI of 250, classified as “hazardous”. Is exercising in this pollution dangerous?<\/p>\n\n\n\n

\"Delhi
Picture Courtesy: Reuters<\/figcaption><\/figure><\/div>\n\n\n\n

Air Pollution Levels During the Airtel Delhi Half Marathon<\/h3>\n\n\n\n

Every year, thousands of runners participate in Delhi’s annual half marathon. In the past, doctors have called on the event to be postponed due to hazardous air pollution levels. In 2018, Delhi AQI nearly reached 500 as the air quality worsened around the time of the race. <\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

<\/p>\n\n\n\n

How dangerous is running in these extremely poor air quality conditions? Let’s dive into and take a look at when exercise in Delhi air pollution starts to be come harmful. <\/p>\n\n\n\n

The Point When Exercise Becomes Harmful<\/h3>\n\n\n\n

At almost any level of air pollution in Delhi, some amount of exercise is beneficial no matter how bad the pollution is. But the worse air pollution is in Delhi, the less one can exercise for before further exercise becomes harmful. <\/p>\n\n\n\n

Researchers at Cambridge analyzed studies on the benefits of exercise and the harms of air pollution and tried to calculate how bad the air has to be<\/a> for exercise to be harmful. There are lots of different types of pollution, but they focused on particle pollution (PM2.5<\/a>), which the WHO says kills more people than any other pollutant<\/a>. They used biking outdoors as the form of exercise. <\/p>\n\n\n\n

\"Biking
Me biking in the streets of Delhi<\/figcaption><\/figure><\/div>\n\n\n\n

Here\u2019s the cost-benefit analysis in a city with 50 micrograms\/m3 of PM2.5 pollution. That\u2019s about the average level in Shanghai<\/a>, but half the average level in Delhi of around 100 micrograms\/m3. For comparison, the WHO annual limit is 10 micrograms<\/a>.<\/p>\n\n\n\n

First check out the green circle, the tipping point. Biking outside is beneficial to lifespan (in other words, \u201cnot dying\u201d) up to about 70 minutes.<\/p>\n\n\n\n

\"When<\/figure><\/div>\n\n\n\n

Then check out the red circle, the breakeven point.<\/p>\n\n\n\n

\"When<\/figure><\/div>\n\n\n\n

At about 300 minutes it actually starts to become harmful. But at that point you\u2019ve been biking for almost five hours, so you need a break anyway. But Delhi averages higher levels of air pollution. At what point does exercising in Delhi’s typical pollution become harmful?<\/p>\n\n\n\n

Exercising in Delhi Pollution<\/h2>\n\n\n\n

In Delhi, estimates show the optimal amount of time to bike in typical Delhi pollution levels of 100 \u03bcg<\/em>\/m3 is 30 minutes. Up to this level, the health benefits of biking outweigh the harmful effects of pollution. <\/p>\n\n\n\n

But after 30 minutes of biking, further biking starts to become harmful to one’s health (the tipping point). And once 90 minutes of biking is hit, the total workout becomes a net negative to one’s health. <\/p>\n\n\n\n

\"When<\/figure><\/div>\n\n\n\n

But keep in mind, this is only considering PM2.5 pollution<\/strong>. It does not take into account any gas pollutants like ozone or NO2. So the total effect of all air pollutants would be worse.<\/p>\n\n\n\n

Also, the 100\u03bcg<\/em>\/m3 pollution level used here is only the average PM2.5 level in Delhi. Delhi’s air pollution can be a lot worse (or better) depending on the day. <\/p>\n\n\n\n

Want to check when exercise becomes harmful for pollution levels higher or lower than Delhi’s average 100 \u03bcg<\/em>\/m3? Check out this chart<\/a> to determine the optimal amount of exercise depending on the outdoor PM2.5 levels. <\/p>\n\n\n\n

What about the Airtel Delhi Marathon?<\/strong><\/p>\n\n\n\n

According to the chart, assuming a run time of 2 hours for the half marathon, running would only start to be harmful after 2 hours if air quality levels were under 15 micrograms\/m3 or around an AQI of 56. The run in total would have a negative impact on health at levels of 60 micrograms\/m3 or AQI of 152.<\/p>\n\n\n\n

Bottom line: <\/strong>At an average Delhi PM2.5 level of 100\u03bcg<\/em>\/m3, exercise outside without a mask is beneficial until the 30-minute mark. <\/p>\n\n\n\n

But, but\u2026<\/strong><\/p>\n\n\n\n

Keep in mind this is an estimate. It is based on epidemiology research, but it uses lots of assumptions. There are lots of factors that could change the equation:<\/p>\n\n\n\n