West Midlands Ambulance Service has experienced a noticeable spike in call-outs linked to breathing problems and chest pains.
Daily figures for calls reporting breathing or chest problems were largely level at around 460 on Friday, Saturday and Sunday last week.
But the corresponding figures for the first three days of this week were 547, 510 and 501.
The service covers Shropshire, Staffordshire, Warwickshire, Herefordshire and Worcestershire.
Higher numbers of complaints about breathing difficulties are thought to have been brought on by record pollution levels in recent days.
Air pollution in the east of England reached the top of the scale as a 'perfect storm' of conditions blanketed parts of the country.
Our region is one of the worst-affected by "very high" levels of air pollution today, with much of the East stuck under a cloud of smog.