China Open semi-finalist Grigor Dimitrov said Saturday he suffered a headache and cough during several “terrible” days in notoriously polluted Beijing.

The 26-year-old Bulgarian exited the tournament in three sets to world number one Rafael Nadal, on a day when the outside hard court in the Chinese capital appeared shrouded in smog.

“I think the toughest part is when you come from Europe, and the first three days is not easy,” he said following his defeat, asked if he feared for his health playing in the conditions.

“But, I mean, what can you do about it? If you think about it, there’s not much you can do.

“I just know the feeling: the first three days are absolutely terrible I think for everybody.

“A bit of a headache, we’re coughing a little bit.

“The first match, the first set, was a little bit of a test for that, just to kind of see where I’m at.”

The world number eight said he attempted to “sweat it out” soon after landing in Beijing, which is frequently blighted by heavy smog.

China is waging a “war on pollution” and says it is committed to improving the air in the capital and other cities after rapid urbanisation brought traffic congestion, pollution and sprawl.