This part of rural Essex has one of the highest concentrations of surviving timber framed buildings - including my listed cottage.

BBC: Meet our campaigners

The highest concentrations of performers and people are in the Old Town.

BBC: Edinburgh: Not just a pretty festival

And some of the highest concentrations are coming out through the Thames.

BBC: Thames archive reveals long nitrate rise

Airborne contamination continues to cross the western states, the new data shows, and Boise has seen the highest concentrations of radioactive isotopes in rain so far.

FORBES: Radiation Detected In Drinking Water In 13 More US Cities, Cesium-137 In Vermont Milk

Concentrations of CO2 reached 389 parts per million in 2010 - the highest such concentrations since the start of the industrial era in 1750.

BBC: No let up in greenhouse gas rise

An earlier study involving leukaemia cells yielded even more impressive results - this could be because leukaemia cells have one of the highest iron concentrations among cancer cells.

BBC: Chinese remedy 'may fight cancer'

DC, has one of the country's highest concentrations of specialist physicians but some of the poorest indicators of general health.

ECONOMIST: The map of well-being

According to the Intergovernmental Panel on Climate Change, a scientific intergovernmental body, concentrations of carbon dioxide in the atmosphere are now at their highest levels for at least 650, 000 years.

CNN: Global warming threatens forests, study says