Progress in regulating lead (Signal)

The hazardous properties of lead and its impacts on environmental and human health have been known for a long time. The health risks associated with lead include neurodegenerative, cardiovascular, renal and reproductive effects, and developmental neurotoxicity. Epidemiological studies have reported an association between early-life lead exposure and adverse developmental impacts. These impacts include detrimental effects on neuromotor function, academic achievement, behaviour, attention, executive function, and auditory and visual functions. Only in recent decades have the adverse impacts of low-level lead exposure been fully understood. Research has shown significant neurological damage in children even at very low levels of lead exposure.

To address these issues, regulators have targeted a host of major lead uses and there is good evidence that these historical measures have been effective in protecting public health. Controls on a range of sources of lead, in particular leaded petrol, have resulted in significant reductions in exposure at the population level. In the EU, the removal of lead from products such as paint, glass, wheel weights, solders and petrol proceeded under EU directives. This resulted in a trending decline in average blood lead concentrations across populations. For example, studies on Swedish children by Strömberg et al. found that mean blood lead concentrations decreased from approximately 60 µg/L in 1978 to 25 µg/L by 1994 — during the period that lead was gradually eliminated from petrol — with further reductions observed (from 20µg/L to <15 µg/L) between 2001 and 2007. Similar significant reductions in blood lead concentrations were documented in other European countries over this time. Recent studies show blood lead concentrations across Europe range from 2.4 µg/L to 42 µg/L based on the latest available data. However, as major historical sources of lead exposure have been regulated, other sources have grown more significant. Lead continues to be among the top ten chemicals of major public health concern globally, including in the EU.

More recently, the EU has addressed additional uses of lead both in pigments (lead sulfochromate yellow and lead chromate molybdate sulfate red pigments, formerly used to give colour to paints and plastics), and in aviation fuels.

Recent research has uncovered more evidence regarding the environmental hazards associated with lead. Lead is now recognised as a non-threshold developmental neurotoxicant and adverse impacts on wildlife populations due to lead exposure have been clearly documented.

The remaining non-essential uses of lead have therefore come into focus, especially when they result in lead dispersal into the environment and are an ongoing concern regarding public health and environmental impacts. In the EU, the recently adopted restriction on the use of lead gunshot in wetlands and the proposed restrictions on lead in ammunition and fishing gear represent a significant escalation of lead risk management, in particular regarding non-essential uses.

In the EU, at least 135 million birds are at risk of primary poisoning from lead gunshot, 14 million are at risk of secondary poisoning and 7 million are at risk from the ingestion of fishing sinker and lures (primary poisoning). To address these risks the proposed restriction would reduce lead releases by ~630kt over the next 20 years.

Evidence to evaluate the performance of future lead risk management actions could include; reduced production volumes, reduced blood lead concentrations and incidences of poisonings, and ultimately increased wildlife population levels. For example, mute swan population data from the UK between 1970 and 2012 shows that a ban on lead fishing gear resulted in population recovery. Historical experience with lead fishing gear restrictions illustrates that the proper design of such measures is important to ensure they are effective. Indicators for the effectiveness of chemicals legislation at the ‘outcome level’ (such as those based on human and wildlife biomonitoring or measurements in food or water, and increased wildlife population numbers) are therefore critical, in addition to indicators at the production volume level, for example.  

The case of lead risk management also illustrates how a regulatory requirement for the proactive safety assessment of alternatives has impacted the market (which can be mapped to the objective of developing safe and sustainable chemicals and materials in the Chemicals Strategy for Sustainability and the safe and sustainable by design (SSbD) framework). In certain jurisdictions, where restrictions exist on the use of lead ammunition in specific habitats such as wetlands, there are also accompanying requirements for alternative non-lead ammunition to be made from materials that meet ‘non-toxic’ standards as defined by regulation. A non-toxic shot is defined as any shot type that does not cause adverse effects or death when ingested by birds. Alternatives must be composed of materials approved as non-toxic by the US Fish and Wildlife Service, as those identified in Section 507.1 (Title 14, CCR) are considered certified. For example, in North America, alternatives to lead ammunition must be approved by the US Fish and Wildlife Service as non-toxic alternatives to lead. These regulations heavily influence the market for non-lead ammunition, as all products must meet these standards to ensure a market. This provides a working example where elements of SSbD are being applied in practice.