Multiple Isotope Fingerprints to Identify Sources and Transport of Agro-Contaminants -D1.50.18


Background:

Agriculture is the main source of pollution in rivers and streams and this has a direct negative impact on human health. A major knowledge gap regarding pollution in agro-ecosystems is source identification and apportionment, which requires more data, research and integration of approaches. When pollutants from multiple sources to an agro-ecosystem occur, traditional techniques cannot help in evaluating the relative contribution of the different sources.

Objective:

This Coordinated Research Project (CRP) planned for 5 years (2018–2022) aims to
(i) identify and apportion macronutrient and micro-contaminant inputs in agro-ecosystems using an integrated isotope approach
(ii) develop, evaluate and standardize an integrative isotope approach for identifying and apportioning sources of contaminants in agro-ecosystems
(iii) apply the combined approach to different agro-ecosystems to control contaminants
(iv) provide guidelines and decision trees for adapting and applying the toolbox
(v) support adaptive land and water management and conservation practices to reduce pollutants from agriculture into soil and water bodies.

The nuclear techniques to be applied include
(i) Compound-specific isotope analysis (CSIA) to determine the fate of micro-contaminants in soils and water
(ii) Stable isotopes analyses of other solutes: δ15N-NO3, δ18O-NO3 δ15N-SO4, δ18O-SO4 and water δ2H-H2O, δ18O-H2O δ13C-POM, δ15N-POM and
(iii) The oxygen isotope ratio of dissolved inorganic phosphate (δ18Op).

Participants:

Fifteen countries participate in this CRP: Australia, Austria, China, France, Germany, Ghana, India, Ireland, Morocco, Romania, Slovenia, Sri Lanka, Switzerland, Viet Nam, United Kingdom.

Activities:

The First Research Coordination Meeting (RCM) was held on 2–6 July 2018 in Vienna, Austria. The draft guidelines on following topics were presented and discussed:

  • Designing a water sampling program for stable isotopes studies of agricultural pollution
  • Compound specific isotope analysis for investigation the source and transport of pesticides from soils to water bodies
  • Oxygen isotopes in phosphate for tracing sources of P in soil and catchment. Individual workplans were discussed and finalized.

The Second RCM aimed to review the Progress made since the first RCM and to develop a workplan and activities to realize the project outputs was held virtually from 1 to 4 March 2021. The achievements to-date are:

  • A new and field validated protocol on the use of (δ18Op) as forensics in water quality investigations to distinguish between fertilizer phosphorus from agriculture and sewerage available to MSs
  • A new silver phosphate (Ag3PO4) reference material for δ18Op analysis was developed for inter-laboratory comparison to ensure quality assurance measurements
  • Database of stable isotope values for commercial pesticide formulations and passive samplers to facilitate CSIA analysis developed and tested.
  • In Vietnam, stable isotopes ware use to distinguish waste from domestic water waste and inorganic fertilizer usage by the local farmers as the main sources of nutrients release in the Nhue sub-catchment.
  • In Slovenia δ15N-NO3 and δ18O-NO3 analysis showed that Soil N (contributing 70-80%) was the main source of nitrate pollution in groundwater in intensive fruit and vegetable production areas.

The CRP participant made 13 presentations in the European Geosciences Union (EGU) during 2019 and 2020.

The third RCM is planned to be held on 25-28 July 2022

Project Officer:

Joseph Adu-Gyamfi and Lee Heng