A simple detector could help conservators at World Heritage sites in the developing world understand and protect against atmospheric pollutants that can damage valuable artifacts.

 

The pollutant-measuring device has been prototyped by Henoc Agbota, an engineer at University College London, United Kingdom, and presented at a conference marking the end of a five-year funding programme for heritage science run from the university.

 

Agbota's work was prompted by last year's decision by UNESCO (the UN Educational, Scientific and Cultural Organization) that its World Heritage Committee would begin asking their certified sites to provide yearly figures for atmospheric pollutant levels. In response, Agbota surveyed 25 developing world sites and found that few had the capacity to do this.

 

Agbota's instrument consists of a series of so called piezoelectric quartz crystals — which generate electric currents as they expand or contact by minute amounts — coated with varying thicknesses of copper, iron, nickel or tin. As pollutants absorb to these metallic surfaces, they change the crystals’ mass, altering the electrical output and allowing pollution levels to be calculated.

 

The prototype can detect oxides of sulphur and nitrogen, ozone and humidity — all of which can accelerate artifact degradation.

 

Agbota says the hardware needed to build the detector costs less than £400 (about US$640) and he hopes it could be produced cheaply at scale. He notes that the nearest competitor on the market, the OnGuard 3000, manufactured by US firm Purafil, costs much more.

 

Agbota's device was tested at several heritage sites in developing nations, including the Abomey Palaces, and has had good feedback. As a result, he says, "one site in Kenya actually decided to move part of their collection to a less-polluted location".