National Assessment of Lead Concentrations in Drinking Water in Hungary

Lead remains a public health priority, in spite of long-standing mitigation efforts. In drinking water, the source of lead is primarily the domestic distribution system. Thus, regulatory compliance monitoring fails to capture the magnitude of the problem. In order to assess lead concentrations in drinking water and identify populations at risk of lead exposure via drinking water, a nationally representative survey was carried out in Hungary. Municipalities were categorized and, where necessary, subdivided into neighborhoods based on the type of municipality, the corrosive nature of the supplied drinking water, and the potential presence of lead pipes in the mains and the domestic distribution systems. A total of 58 representative residential areas were selected for a 6-month sampling campaign. Random daytime (RDT) and 1 min flushed samples were collected from residential and public buildings and analyzed for lead by inductively coupled plasma mass spectrometry. Non-compliance rates were significantly higher in buildings built before 1945 (25% compared to 7% in newer buildings), when the use of lead pipes was general practice. Flushing reduced lead levels significantly, corresponding to 14% and 6% non-compliance in the RDT and flushed samples, respectively. No association was found with corrosive versus protective water quality. High risk areas were primarily identified in the capital and historic centers of cities. The results were translated into public information tools including a searchable map of lead risk areas and a simplified risk assessment tool for consumers. The survey outcomes also support national risk assessment for lead in drinking water, an upcoming obligation under the recast European Union drinking water regulation.