From the available documentation, we identified three likely major reasons for the slow progress to phase out leaded gasoline in New Zealand. These included: (1) industry power in the form of successful lobbying by the lead additive supplier, Associated Octel; (2) the absence of a precautionary principle as part of risk management policy and (3) weak policymaking machinery. Given the complexity and importance of the issues, further analysis of the historical developments is clearly warranted, together with comparative analyses of the lead additives endgame in other countries. Further research to clarify the importance of these different reasons could be based on multiple key informant interviews and a more comprehensive examination of official documentation.
Nevertheless, some of the findings in this New Zealand case study are consistent with the delays observed in other countries that were acting to phase out lead additives [
64,
65]. Similar findings apply to responses to the hazards of lead piping [
7] and leaded paint [
66,
67]. An extreme example of this was in France, where the dangers of lead in paint had to be more or less rediscovered in the mid-1980s [
68]). These laggardly responses are familiar in instances of other environmental health hazards such as asbestos, second-hand smoke and greenhouse gases. In the case of second-hand smoke, for example, there have been lags of several decades from the time a hazard to health was identified and the enactment of regulations that adequately restrict smoking in public places (with the historical scientific evidence detailed in a Surgeon General's Report [
69], and current laws detailed by Novak [
70]).
The New Zealand experience illustrates the weakness in decision-making that comes when no single government agency akin to the US EPA has overall responsibility for an environmental health issue. This weakness should be addressed directly in the course of any initiatives to place a precautionary principle at the heart of policy formation. Strengthening policymaking processes for environmental health issues also requires appropriate in-house technical expertise in central government, adequate resourcing to resist industry pressure, and openness to input from the expertise in civil society provided by non-governmental organisations and universities.
Yet even with more appropriate structural arrangements and processes it cannot be assumed that EPA-like bodies will always work optimally to protect public health. The US EPA, for example, refused to consider lead a criterion pollutant until it was sued by National Resources Defense Council [
65]. Even now the current US air lead standard is 1.5 μg/m
3, three times that recommended by WHO.
For small countries such as New Zealand, the lack of appropriate government agencies to address such environmental health issues might be ameliorated in the future by drawing on technical support from international bodies such as the WHO. These bodies can also have the capacity to develop relevant international treaties such as the Framework Convention for Tobacco Control [
71].