New Delhi is in trouble. It is desperately trying to reduce pollution, and some of the steps it’s taking are admirable. But they don’t seem to be making a difference.

One can see the pollution hanging in the air. Worse, though, one can taste it. It’s grit on the tongue. It’s a scratch in the throat. It’s a tickle-cough. It’s a smell.

The Hindustan Times reported that the air quality in Delhi reached the “very poor” level Dec. 29, and was forecast to worsen Dec. 30. For those interested in numbers, the PM10 was recorded at 304, and the PM2.5 at 197 micrograms per cubic meter. The normal levels are 60 and 100 respectively.

PM stands for particulate matter. The EPA describes it as “a mixture of solid particles and liquid droplets (including acid) found in the air. Some particles, such as dust, dirt, soot or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope.”

PM10 is especially dangerous because it can get sucked deep into the lungs and even work into the bloodstream. People with heart or lung diseases like congestive heart failure or asthma are advised to avoid any exertion in this weather.

In 2015, more than 6,500 people died of respiratory illnesses, one of the leading causes of death in India. Many people who work outside wear masks over their mouths and noses, but most don’t. A colleague stepped out of the hotel the other morning and asked one of the doormen if he smelled the smoke that was quite obvious to us in the air. He considered the question and replied no, everything smelled normal to him.

I use a CPAP machine at night for apnea. At home, I sometimes forget to change the filter. On my old machine. it was a nylon cube about three-fourth inch square, and after a month or so, it looked pretty much white and new. Three years ago, when I was here in Delhi, I took the filter out after two weeks. It looked like a piece of coal, jet black and sooty.

At the time, we were staying in a guesthouse with no air conditioning. This time, I’m in a good hotel with a ventilation system. But after five days, the filter on my CPAP is the color of a fine charcoal suit. The hotel’s system isn’t doing much to stop the pollution for us here.

The reason?

There is, of course, not just a single one. Delhi is a city of 20 million people. The Hindustan Times says the government reports there are 10 million cars registered. That’s one car for every two people, including children. A government report estimates car exhaust fumes contribute 25 percent of the city’s pollution.

Farmers in the rural areas surrounding New Delhi also contribute to the deadly haze. The only way they have of clearing stalks from the rice paddies is to burn them. Smoke from thousands of fires shroud the city and combine with vehicle fumes and dust from constructions sites. Open wood and paper fires line the streets at night as homeless people struggle to stay warm.

The result is literally a choking, acrid pall that settles over the city, and in a temperature inversion as Delhi has had for the last few days, it does not dissipate.

The city is trying to make changes. It has banned trucks that belch black smoke into the atmosphere. It has tried road rationing. Cars with odd-numbered license plates alternate with even-numbered plates on the road each day. It’s trying to get rid of cars more than 15 years old, in poor condition and with less pollution control. But it doesn’t seem to work.

Public transportation is woefully inadequate here. In a city of 20 million people, there are fewer than 5,000 buses. They are unreliable because they can’t get through the traffic jams created by the cars people drive because the bus is unreliable. The train system is already at capacity. There is no other way than autos, motorcycles and tuk-tuks — the three-wheeled motorized rickshaws — to get around. Interestingly, though, many of the auto-rickshaws are powered with compressed natural gas, which emits less pollution than gasoline, or would if the engines were tuned. Really, the motors on those things aren’t much more than a garden tractor.

I’m relatively healthy, if a little chunky around the middle, and I’m only staying here two weeks. The pollution is going to annoy me but not kill me. I’m going home to the clean air of a Midwestern city. I’ll cough out the soot in my lungs over a few weeks, try to remember the pollution I left behind in New Delhi, and I hope I remember to say a prayer of thanks every morning.