Preliminary analysis of the data collected suggested that the clean air - as well as the optimal temperature and humidity - was among the factors leading to the high number of personal best performances at the competition.

This included a women-only half marathon world record for women's winner Peres Jepchirchir of Kenya, who finished in a time of 1 hour 05min 16sec.

Men's winner Jacob Kiplimo of Uganda, ran a new Championship record too, as well as a new national record in a time of 58min 49sec.

A total of 14 national records were set in the men's race, with a further eight coming in the women's race.

There were 69 personal bests set in the men's race from 117 finishers and 65 personal bests in the women's race from 101 finishers.

Two Kunak air quality monitors were used in Gdynia - one at a fixed position near the start line and another attached to a bicycle which followed the athletes around all four laps of the races.

This data was gathered across an 18-hour period in the city and pending validation could show that the low pollution came from a combination of the location being near the sea, the timing of the competition and the meteorological conditions of the day.

"The data we collected suggest that conditions in Gdynia were optimal for runners and spectators," World Athletics health and science department manager Paolo Emilio Adami said.

"The strong winds and rain of the first day cleared the air and the levels of particulate matter that we recorded were the lowest we have so far measured in road races. 

"Levels of gasses, ozone and nitrogen dioxide were consistent with the environmental conditions and the location of the city. 

"From a personal standpoint, it was fantastic to cycle next to the athletes in both the men's and women's races."

Most of World Athletics' Air Quality Project has been conducted in stadiums so far, but has stated that road races in cities where pollution can be high, can give researchers more information about air pollution during races.

World Athletics is set to implement air monitoring programmes in the future, which will set air quality standards for major championships and sanctioned events, following the World Health Organization's standards.

These guidelines indicate that reducing particulate matter pollution from 70 to 20 micrograms per cubic metre, air pollution-related deaths can be cut by approximately 15 per cent.