Flexing the PECs: Predicting environmental concentrations of veterinary drugs in Canadian agricultural soils

Abstract

Veterinary drugs administered to food animals primarily enter ecosystems through the application of livestock waste to agricultural land. Although veterinary drugs are essential for protecting animal health, their entry into the environment may pose a risk for nontarget organisms. A means to predict environmental concentrations of new veterinary drug ingredients in soil is required to assess their environmental fate, distribution, and potential effects. The Canadian predicted environmental concentrations in soil (PECsoil) for new veterinary drug ingredients for use in intensively reared animals is based on the approach currently used by the European Medicines Agency for VICH Phase I environmental assessments. The calculation for the European Medicines Agency PECsoil can be adapted to account for regional animal husbandry and land use practices. Canadian agricultural practices for intensively reared cattle, pigs, and poultry differ substantially from those in the European Union. The development of PECsoil default values and livestock categories representative of typical Canadian animal production methods and nutrient management practices culminates several years of research and an extensive survey and analysis of the scientific literature, Canadian agricultural statistics, national and provincial management recommendations, veterinary product databases, and producers. A PECsoil can be used to rapidly identify new veterinary drugs intended for intensive livestock production that should undergo targeted ecotoxicity and fate testing. The Canadian PECsoil model is readily available, transparent, and requires minimal inputs to generate a screening level environmental assessment for veterinary drugs that can be refined if additional data are available. PECsoil values for a hypothetical veterinary drug dosage regimen are presented and discussed in an international context. Integr Environ Assess Manag 2017;13:331–341. © 2016 Her Majesty the Queen in Right of Canada. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. Reproduced with the permission of the Minister of Health.

Potential Reuse of Wastewater Containing Recalcitrant Organic Compounds, Treated by Advanced Oxidation Processes

“…Municipal wastewater comprises mainly C, N, and P, in proportions, known as “C:N:P ratios,” of 100:14:1. Crop wastewater and LSWW stand out for their high content of P and N in relation to C, with C:N:P ratios around 20:4:1 for CropWW (Bardi et al 2017; Ortiz‐Marin et al 2020) and 100:35:1 for LSWW (Bardi et al 2017; Mendivil‐García et al 2020), derived from the content of organophosphate pesticides and physiological residues containing veterinary drugs (Kullik and Belknap 2017).…”

Debates, Dilemmas, and Discoveries

“…Municipal wastewater comprises mainly C, N, and P, in proportions, known as "C:N:P ratios," of 100:14:1. Crop wastewater and LSWW stand out for their high content of P and N in relation to C, with C:N:P ratios around 20:4:1 for CropWW (Bardi et al 2017;Ortiz-Marin et al 2020) and 100:35:1 for LSWW (Bardi et al 2017;Mendivil-García et al 2020), derived from the content of organophosphate pesticides and physiological residues containing veterinary drugs (Kullik and Belknap 2017).…”

Long-Term Exposure of Agricultural Soil to Veterinary Antibiotics Changes the Population Structure of Symbiotic Nitrogen-Fixing Rhizobacteria Occupying Nodules of Soybeans (Glycine max)

“…I n commercial North American and European agriculture, antibiotic medicines are introduced into agricultural soil through normal farming practice (1). Some antibiotics are used for controlling bacterial diseases of some crops, for example, streptomycin or tetracycline to control the loss of production from fruit trees due to infection of the blossoms with Erwinia amylovora (2).…”

“…Some antibiotics are used for controlling bacterial diseases of some crops, for example, streptomycin or tetracycline to control the loss of production from fruit trees due to infection of the blossoms with Erwinia amylovora (2). Manure from medicated animals either applied as a fertilizer or excreted directly on the pasture will contain drug residues that are excreted intact (1)(2)(3)(4)(5)(6)(7). Antibiotics that are not degraded during the treatment of municipal sewage and that sorb to organic matter will partition into the recovered sludge (8)(9)(10).…”