Dynamic Source Distribution and Emission Inventory of a Persistent, Mobile, and Toxic (PMT) Substance, Melamine, in China

Abstract

Persistent, mobile, and toxic (PMT) substances are affecting the safety of drinking water and are threatening the environment and human health. Many PMT substances are used in industrial processing or consumer products, but their sources and emissions mostly remain unclear. This study presents a long-term source distribution and emission estimation of melamine, a high-production-volume PMT substance of emerging global concern. The results indicate that in China, approximately 1858.7 kilotonnes (kt) of melamine were released into the water (∼58.9%), air (∼27.0%), and soil systems (∼14.1%) between 1995 and 2020, mainly from its production and use in the decorative panels, textiles, and paper industries. The textile and paper industries have the highest emission-to-consumption ratios, with more than 90% emissions per unit consumption. Sewage treatment plants are the largest source of melamine in the environment for the time being, but in-use products and their wastes will serve as significant melamine sources in the future. The study prompts priority action to control the risk of PMT substances internationally.

Graph Convolutional Network-Enhanced Model for Screening Persistent, Mobile, and Toxic and Very Persistent and Very Mobile Substances

“…8 The current identification methods for PMT/vPvM substances by traditional experimental analysis remains a huge challenge due to the incapability of the screening emerging contaminants in large scale. 9,10 An accurate and robust ready-to-use tool for highthroughput screening of PMT/vPvM substances is urgently needed. 11,12 Machine learning and deep learning-driven models have emerged as efficient screening methods alternative to the experimental determination of PMT/vPvM and PBT/vPvB substances.…”

“…The persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances can persist for a long time and spread in the urban water circulation system, posing threats to sustainable, safe, and healthy drinking water. − With the increasing international attention on PMT/vPvM substances, they are regarded with an equal concern level as persistent, bioaccumulative, and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances by the German Environment Agency. − The definition of PMT/vPvM substances was updated in 2022 by the European Union classification, labeling, and packaging (CLP) to match the future management of chemicals . The current identification methods for PMT/vPvM substances by traditional experimental analysis remains a huge challenge due to the incapability of the screening emerging contaminants in large scale. , An accurate and robust ready-to-use tool for high-throughput screening of PMT/vPvM substances is urgently needed. , …”