Impact of drinking water treatment processes on the residues of plant protection products for consumer and aquatic risk assessment: theoretical and experimental studies

Pesticides residues can occur in ground and surface waters, and potentially react with chemicals used for water disinfection treatments, such as chlorine. This can lead to the formation of unknown reaction products, which can be more toxic and/or persistent than the active substances themselves, and therefore become a potential risk for human health and environment. Thus, in the framework of the EU Regulation 1107/2009, the identification of these by-products and their potential risk should be assessed. Within the European Food Risk Assessment (EU-FORA) Fellowship Programme, the fellow studied the behaviour of herbicides belonging to the families of imidazolinones and sulfonylureas in waters treated with chlorine disinfectants. Due to their physicochemical properties, these herbicides are susceptible of reaching natural waters. In fact, some of them have been detected in water monitoring programmes. During the experimental part of the present work programme, reactions between the active substances and the most used chlorine disinfecting reactants (hypochlorite and chloramines) were performed. Degradation kinetic parameters such as half-lives and degradation constants were calculated. Results showed that herbicide degradation was both pH and chlorine/chloramines concentration dependent. In order to identify the degradation by-products, high-resolution mass spectrometry experiments were performed, and a possible route of formation of these compounds was proposed. Finally, their risk assessment was carried out by using tox/ecotoxicological properties determined by QSAR methodology and FOCUS modelling for hazard and exposure assessment, respectively. These results will contribute to the definition of a risk assessment scheme for pesticides by-products potentially occurring in drinking water.

Radical Nephroureterectomy Tetrafecta: A Proposal Reporting Surgical Strategy Quality at Surgery

Background

Standardized methods for reporting surgical quality have been described for all the major urological procedures apart from radical nephroureterectomy (RNU).

Objective

To propose a tetrafecta criterion for assessing the quality of RNU based on a consensus panel within the Young Association of Urology (YAU) Urothelial Group, and to test the impact of this tetrafecta in a multicenter, large contemporary cohort of patients treated with RNU for upper tract urothelial carcinoma (UTUC).

Design, setting, and participants

This was a retrospective analysis of 1765 patients with UTUC treated between 2000 and 2021.

Outcome measurements and statistical analysis

We interviewed the YAU Urothelial Group to propose and score a list of items to be included in the “RNU-fecta.” A ranking was generated for the criteria with the highest sum score. These criteria were applied to a large multicenter cohort of patients. Kaplan-Meier curves were built to evaluate differences in overall survival (OS) rates between groups, and a multivariable logistic regression model was used to find the predictors of achieving the RNU tetrafecta.

Results and limitations

The criteria with the highest score included three surgical items such as negative soft tissue surgical margins, bladder cuff excision, lymph node dissection according to guideline recommendations, and one oncological item defined by the absence of any recurrence in ≤12 mo. These items formed the RNU tetrafecta. Within a median follow-up of 30 mo, 52.6% of patients achieved the RNU tetrafecta. The 5-yr OS rates were significantly higher for patients achieving tetrafecta than for their counterparts (76% vs 51%). Younger age, lower body mass index, and robotic approach were found to be independent predictors of tetrafecta achievement. Conversely, a higher Eastern Cooperative Oncology Group score, higher clinical stage, and bladder cancer history were inversely associated with tetrafecta.

Conclusions

Herein, we present a “tetrafecta” composite endpoint that may serve as a potential tool to assess the overall quality of the RNU procedure. Pending external validation, this tool could allow a comparison between surgical series and may be useful for assessing the learning curve of the procedure as well as for evaluating the impact of new technologies in the field.

Patient summary

In this study, a tetrafecta criterion was developed for assessing the surgical quality of radical nephroureterectomy in patients with upper tract urothelial carcinoma. Patients who achieved tetrafecta had higher 5-yr overall survival rates than those who did not.