6. Toxic Pollutants
6.1 Introduction
This section includes pollutants singled out for control under international protocols to the Convention on Long-range Transboundary Air Pollution, namely the POPs and Heavy metal protocols.
6. 1.1 UNECE Heavy metals and POPs protocols
6.1.1.1 Heavy metals
The draft protocol on heavy metals targets three particularly harmful substances: lead, cadmium and mercury. According to one of its basic obligations, countries have to reduce their emissions of these three metals below their levels in 1990 (or an alternative year between 1985 and 1995). The protocol aims to cut emissions from industrial sources (iron and steel industry, non-ferrous metal industry), combustion processes (power generation, road transport) and waste incineration. It lays down stringent limit values for emissions from stationary sources and suggests best available techniques (BAT) for these sources, such as special filters or scrubbers for combustion sources or mercury-free processes. The protocol requires countries to phase out leaded petrol. It also introduces measures to lower heavy metal emissions from other products, such as mercury in batteries, and proposes the introduction of management measures for other mercury-containing products, such as electrical components (thermostats, switches), measuring devices (thermometers, manometers, barometers), fluorescent lamps, dental amalgam, pesticides and paint.
6.1.1.2 POPs
The draft protocol on persistent organic pollutants focuses on a list of 16 substances, which have been singled out according to certain risk criteria:
The ultimate objective is to eliminate any discharges, emissions and losses of POPs. The protocol bans the production and use of some products outright (aldrin, chlordane, chlordecone, dieldrin, endrin, hexabromobiphenyl, mirex and toxaphene). Others are scheduled for elimination at a later stage (DDT, heptachlor, hexachlorobenzene, PCBs). Finally, the protocol severely restricts the use of DDT, HCH (including lindane) and PCBs. Limited uses which are thought to be essential and for which there are no adequate substitutes, can be exempted. For instance, the use of substances like DDT will be allowed for public health emergencies. The protocol includes provisions for dealing with the wastes of products that will be banned. It also obliges countries to reduce their emissions of dioxins, furans, PAHs and HCB below their levels in 1990 (or an alternative year between 1985 and 1995). It puts forward best available techniques to cut emissions of these POPs. For the incineration of municipal, hazardous and medical waste, it lays down specific limit values.
Interest in a wide range of toxic pollutants has grown over recent years as their importance in the environment has become recognised and the NAEI has been gradually extended to include these pollutants. Table 6.1 lists the toxic pollutants included in the current inventory together with their total UK emissions in 1996.
| Pollutant | Total 1996 UK emission (kt) |
|
3.881 0.489 3.75x10-3 0.044 0.562 1.24x10-3 |
Heavy metals
|
1.357 0.019 0.016 0.065 1.119 0.292 0.055 0.051 0.083 1.235 |
The level of data available for many of these pollutants is relatively limited and hence the uncertainties associated with these inventories are quite large. However, the inventories are being continuously improved to incorporate new data as it becomes available. During the past year extensive work has been undertaken on improving the POPs inventories and the 1996 NAEI now includes time series data (1990 - 1996) for all the POPs and a speciated inventory for PAHs. Similarly, there have been revisions of the heavy metals inventories.
