Population-based human biomonitoring in the ‘Land of Fires’ area: innovations in study design and procedures

摘要

According to the WHO, approximately a quarter of deaths recorded worldwide in 2012 were ultimately caused by unhealthy environmental factors, including air, water and soil contamination, indoor and electromagnetic pollution, agricultural methods and occupational exposure [1]. In advanced countries, industrialization is usually one of the main culprits for pollution, which can be interpreted as the downside of economic growth and progress. In the provinces of Naples and Caserta in the Campania region of southern Italy, which encompass a total of 195 municipalities and include grazing and farming lands, one contributing factor to environmental pollution has been illegal waste trafficking – a rare scenario in Europe and other industrialized countries. According to Legambiente, one of the most authoritative nongovernmental Italian organizations for environmental protection [2], an estimated 10 million tons of hazardous waste – including waste from the metallurgy and leather industries, dust from fume filters, paint sludge, liquid waste contaminated with heavy metals, asbestos and polluted land from remediation activities – were either buried underground or abandoned in open air in these areas during the years 1991–2014. Waste that is not buried is usually burned to remove traces; hence the nickname ‘Land of Fires’ (LoF), because thousands of fires have been reported. Over the past decades, its profitability and simplicity have fueled the phenomenon of illegal waste trafficking in the LoF, which has only been partially contained by the numerous legal investigations conducted so far and the multiple ad hoc legislative interventions, such as the Law 6/2014 [3]. The threats posed by open-air incineration and burial of hazardous waste have generated fears of contamination in both the resident population and consumers of local food products, causing social tensions and both image and economic damage for the local food producers. From an epidemiology perspective, there is consistent evidence that citizens dwelling in the provinces of Naples and Caserta show some excess risk for all-cause mortality and various types of cancer compared with the regional average [4], especially in municipalities located in the northern part of the Naples province and the southeastern part of the Caserta province, where most clusters of slightly to moderately increased cancer mortality [5] have been identified. These findings have been confirmed by the SENTIERI epidemiological study conducted in the LoF municipalities [6], which showed an overall increased risk of all-cause mortality of 5–10%, with higher increases for certain cancers in certain areas (e.g., bladder cancer in the Naples province [7]). Nevertheless, studies have failed to prove a cause–effect relationship between waste exposure and increased cancer-related and all-cause mortality in the area; the presence of dumping sites was not consistently associated with clusters of increased cancer incidence [8]. While the exact magnitude of the consequences of the LoF phenomenon for human health is yet to be determined, the area’s bad reputation has severely harmed the economy over the years. As an example: in 2014, revenues from one of the typical products of Campania, water-buffalo mozzarella, dropped by 57 million Euros [9].