Even in the relative cleanliness of Lenin Hills, where I live in the south of the city and where the air is kept clear by southwesterly winds, the atmosphere was still thick and heavy.
After consulting the Environmental Pollution Monitoring Laboratory, I learned that the smog had been caused by forest fires, started by weekend picnickers. It was aggravated by the atmospheric conditions: little or no wind to blow the smog away.
Monday is also the day when caretakers from large blocks of flats burn rubbish in the back yard. That added to the thickness of the smog and, all in all, it was a great start to the week.
Then Tass news wire opened up. Cases of mushroom poisoning in south Russia and Ukraine were on the rise, the agency said. There had been 500 cases of people eating poisoned mushrooms in Russia and Ukraine and 60 of them had died.
Two experts at a meeting of the Russian State Committee on Emergency Situations had advanced separate theories about the epidemic. One of them suggested that poisonous toadstools had somehow mutated under influence of natural or unnatural factors and finished up looking like edible mushrooms.
The second version was that edible mushrooms, under the influence of unfavourable weather - this summer, it is drought - grow at the expense of toadstools and somehow absorb poisonous substances from the soil due to the lack of moisture.
There is no known local antidote for the virulent poison produced by a Russian toadstool. Russian health officials have never considered such research necessary because Russians are so adept at distinguishing between toadstools and mushrooms that there has been no cause to invest in developing such a medicine.
This is all distressing for the poor Russians, who are passionately fond of mushrooms, and eat a great variety found in the birch forests. In my experience, they have much greater flavour than the button mushrooms produced commercially, and Russians dry, pickle and salt them to ensure a year-round supply.
Now, all citizens have been urged to stop picking mushrooms for a while, especially in the Voronezh region, 300 miles south of Moscow, where most of the reports of poisoning have occurred. This is the centre of the 'Black Earth' area that covers about 9 per cent of the old Soviet Union. It is fertile grassland soil, with a dark humus layer more than 10 inches thick and chemically neutral.
A classified document dated 9 February, 1990, from the Soviet Health Ministry, came to light in the newspaper Rossiyskaya Gazeta this week, revealing that contamination of essential food products with pesticides and other chemicals had grown threefold. In tests carried out in state laboratories, banned chemicals including DDT, were found in increasing quantities. The newspaper said it was officially accepted that the average 40-year-old citizen has consumed about 28 kilos (32lbs) of toxic chemicals with food grown in the former Soviet Union.
There is no reason why the end of Communism and the Soviet Union has changed any of this. Russia still has no legislation for punishing producers and distributors of poisoned food products.
Which brings me to Tuesday. That is the day when, for the first time since I arrived here last year, I suddenly developed all the symptoms of acute food poisoning, which lasted for a day. I had not been eating mushrooms but had consumed vegetables from the local farmers' market, which - in these months - is supplied from the southern regions of Russia and Ukraine as well as the traditional Transcaucasus suppliers.
I perhaps should admit that my fare included a fine, juicy, oversized tomato with two heads, weighing almost 1lb, that I had been persuaded to purchase by a proud storekeeper in the market who said it had come from 'somewhere in the south'. Tass has not yet reported any victims of 'mutant tomatoes'.