Elke Dopp1
, Santosh Yadav2
, Furquan Ahmad Ansari2
, Kunal Bhattacharya1,2
, Ursula von Recklinghausen1
, Ursula Rauen3
, Klaus Rödelsperger4
, Behnaz Shokouhi1
, Stefan Geh1
and Qamar Rahman2 
1Institute of Hygiene and Occupational Medicine, University Hospital Essen, Germany
2Fibre Toxicology Division, Industrial Toxicology Research Centre, Lucknow, India
3Institute of Physiological Chemistry, University Hospital Essen, Germany
4Institute of Occupational Medicine, University Hospital Giessen, Germany