1. We studied the occurrence in wastewater of pesticides and metabolites from 2014 to 2020 in Greece. Fifty-one compounds were detected belonging to various classes (e.g. fungicides, herbicides, insect repellents and insecticides). The detection profile of these classes remained stable throughout the campaign and fungicides was the most found class. The use of many detected compounds is not approved in Europe and thus, specific actions need to be taken. Finally, we proposed two new wastewater-based epidemiology (WBE) biomarkers to assess the human exposure to DEET and captan.
2. For the first time a high-resolution mass spectrometry non-target approach combined with census data for the identification of public health biomarkers was applied. We developed a robust methodology that can be applied worldwide, provides complementary information compared to other traditional techniques relevant to public health and enables large-scale national coverage with a small number of samples. Wastewater analysis revealed that: cardiac arrhythmias are increased with advancing age; communities with low socioeconomic status were positively associated with markers of cardiovascular disease; lower education was associated with cardiovascular disease and type 2 diabetes; population working in lower skilled occupations had higher prevalence of cardiovascular disease and type 2 diabetes; separated or divorced people were positively correlated with cardiac arrhythmias, cardiovascular diseases, and depression.
3. We applied a WBE approach across the New Year period in three consecutive years to 47 sites in 16 countries. Our study provided a broader insight into new psychoactive substances (NPS) market internationally and established which NPS were most used in the countries. Synthetic cathinones were the most found class followed by phenethylamines and designer benzodiazepines. Highest consumption was recorded for most NPS around the New Year holiday, indicating that consumption increased at parties. Some NPS were detected in specific regions during the initial sampling campaigns and spread to additional sites by the third campaign. These results suggest that reducing NPS use and protecting public health should not only be done at the national level; it requires an organized global campaign. Therefore, organizations, such as the UNODC and the EMCDDA, could adopt a similar wastewater analysis approach as a surveillance tool for NPS.
4. We collected wastewater during New Year period and a summer Festival in Spain. We investigated the prevalence of NPS and illicit drugs at festivals, highlighting the high use of drugs at the peak of each event and the dynamic change in NPS use (presence and absence of substance within six months). It was proved that WBE approach can provide a wealth of data on the prevalence of NPS and illicit drugs in festivals and everyday life. It complements important public health information that can aid health authorities, policy makers and (inter)national organizations to face and suppress illicit drug trade. However, a better and comprehensive understanding of the drug problem requires the collection of data from various sources (e.g. social media, dark web, pill testing, forensic toxicology analyses and emergency departments) and continued collaboration and data triangulation between stakeholders is necessary.
5. We evaluated and highlighted the need to use the WBE approach as a surveillance tool to assess human consumption of psychotropic substances (alcohol, nicotine, and caffeine). This approach can be used to track the achievement of the United Nations Sustainable Development Goals, such as limiting per capita alcohol consumption (goal 3.5) and limiting the use of tobacco and tobacco-related products (goal 3.a). One of the main advantages of this tool is that it can track unrecorded alcohol and nicotine, both illegal and legal, and provide overall indicators of consumption. In addition, it can be applied to monitor total caffeine consumption and assess levels according to the recommended daily safety limit as suggested by the European Food Safety Authority.
Exploitation and dissemination of the results took place through conferences (oral presentations), seminars, meetings with authorities, scientific publications, Researchers' Night, Science is Wonderful, project website and social media.
