The Highways Agency undertakes workplace exposure surveys to ascertain background concentrations of diesel exhaust fumes, carbon monoxide, carbon dioxide, nitrogen oxides, toluene, xylene, ethyl benzene and benzene during the normal working day.
The results are measured against Health and Safety Executive Workplace Exposure Limits and other European exposure limits. This monitoring, which is carried out by an independent organisation, shows that the levels being recorded at the Dartford Crossing are consistently well below set acceptable levels.
Under part 4 of the Environment Act 1995, Dartford Borough Council and Thurrock Council operate Air Quality Management Areas on the A282 adjacent to the crossing. These results can be found on the following websites: