Swanscombe is a small town in the Borough of Dartford in Kent, England. It lies east of Dartford and also north-west of Gravesend, in the civil parish of Swanscombe and Greenhithe. At the 2001 UK census, the Swanscombe electoral ward had a population of 6,418. Swanscombe was important in the early history of concrete. The first concrete manufacturing functions near Swanscombe were opened at Northfleet by James Parker, around 1792, making "Roman cement" from concrete rock brought from the Isle of Sheppey. James Frost opened a works at Swanscombe in 1825, making use of chalk from Galley Hill, having actually patented a new concrete called British Cement. The Swanscombe plant was ultimately acquired by John Bazley White & Co, which ended up being the largest part of Blue Circle Industries when it formed in 1900. It ultimately shut down in 1990. In between 1840 and 1930 it was the largest concrete plant in Britain. By 1882 a number of concrete manufacturers were running across the north Kent area, yet the resulting dirt pollution drove the people of Swanscombe to take lawsuit versus the neighborhood cement jobs. Regardless of numerous technical developments, the trouble continued right into the 1950s, with telegraph lines over an inch thick in white dust. Modern cement kilns in Kent utilizing chimneys 170 m (550 feet) in height are currently stated to be the cleanest on the planet. However, the adjoining Medway towns are reported to be the most polluted inhabited location in the UK, and also the concrete sector contributes to acid rain in Scandinavia.