Contaminants of emerging concern in agricultural systems: a risk to soil and plant health?

为了可持续地为不断增长的人口提供全球粮食，关键是要减少作物对化学化肥(如氮、磷、钾)的依赖，并确定解决缺水问题的替代水供应。农业是可用淡水的最大消费者(70%)，预计到2050年，需求将进一步增加19%。全球磷和钾储量在100年内耗尽，也对未来的化肥供应和我们种植足够粮食的能力构成了重大威胁。确保未来农业生产率的最有希望的选择之一是使用废水处理副产品，包括污泥和处理后的废水(TWW)。然而，日常生活中使用的化学品，包括药品(例如处方和非处方)、个人护理产品(例如肥皂、消毒剂)和纤维(例如塑料)可能会通过废水处理厂并污染TWW和污泥。这些污染物统称为“新出现的关注污染物”(ECs)。我们提高粮食产量和营养含量以满足未来需求的能力可能会受到土壤-植物系统中ECs存在的影响。特别是，药物是具有生物活性的化学物质，它们在农业系统中的存在可能会对植物、土壤和人类健康造成不良的毒性影响。药品现在是无处不在的全球污染物；然而，我们对这些污染物构成的潜在生态系统风险的科学了解很少，特别是在农业系统中。研究已经证实，植物可以积累持续存在于土壤中的药物，但我们对目前使用的1500种药物对植物和土壤健康以及最终作物生产力的影响知之甚少。该研究金第一阶段的拟议研究方案旨在通过联合科学专门知识来探讨：1.与污泥和TWW有关的药物对土壤功能的影响，以维持可持续的农业生产，从而填补这些知识空白。药物的积累和对植物健康的影响以及对作物生产的影响3。评估未来(20-100年)土地利用变化、气候变化以及污泥和废渣使用率的相关变化引起的风险评估第二阶段研究金将利用第一阶段创建的科学平台，调查可能限制农业生产力的更大范围的环境影响，如纳米材料和塑料，并探索缓解已观察到的影响的解决方案。在一些人口使用药物相对较多的国家(如以色列、南欧、美国西南部)，将废水副产品应用于土地是一种公认的做法。已经在接受污泥和TWW的土壤中发现了药物，再加上最近在缺水国家增加TWW用于农业灌溉的努力，迫切需要确定这些化学品在我们农业系统中的全球风险。虽然英国目前没有使用TWW进行农业灌溉，但环境局表示，到本世纪50年代，英国将出现严重的供水短缺。因此，TWW可能会提供一种手段来补充我们对淡水灌溉的需求；然而，必须对这一解决方案进行评估，以确保建立环境安全的协议，促进农业的可持续性。这项研究的结果还将提供有效的证据，供非学术最终用户(如环境监管机构、水工业、农业部门)使用，指导英国退欧后的TWW再利用政策，以确保英国在降低环境中ECs的风险方面保持世界领先地位，同时最大限度地实现可持续再利用。

In order to sustainably secure global food for a growing population, it is critical that crop dependence on chemical-based fertilisers (e.g. nitrogen, phosphorus, potassium) is reduced and alternative water supplies identified which address water scarcity issues. Agriculture is the largest consumer of available freshwater (70%) with demand expected to increase by a further 19% by 2050. The depletion of global phosphorus and potassium reserves within 100 years also pose major threats to future fertiliser supply and our ability to grow enough food.One of the most promising options to secure future agricultural productivity is the use of wastewater treatment by-products, including sludges and Treated Wastewater (TWW). However, chemicals used in our everyday lives, including pharmaceuticals (e.g. prescription and non-prescription), personal care products (e.g. soaps, disinfectants) and fibres (e.g. plastics) can pass through wastewater treatment plants and contaminate the TWW and sludges. These pollutants are referred to collectively as "contaminants of Emerging Concern" (ECs). Our ability to boost yields and nutritional content of food to meet future demand may be impacted by the presence of ECs in soil-plant systems.Pharmaceuticals, in particular, are biologically active chemicals and their presence in agricultural systems could result in undesired toxic effects for plant, soil and human health. Pharmaceuticals are now ubiquitous global contaminants; however, our scientific understanding of potential ecosystem risks posed by these pollutants is scarce, especially in agricultural systems. Research has established that plants can accumulate pharmaceuticals that persist in soils, but we know very little about impacts of >1,500 pharmaceuticals estimated to be in current use on plant and soil health and ultimately crop productivity. The proposed programme of research for the first phase of the Fellowship aims to fill these knowledge gaps by uniting scientific expertise to explore the:1. Impact of pharmaceuticals associated with sludges and TWW on soil functioning in relation to maintaining sustainable agricultural production2. Accumulation and effects of pharmaceuticals on plant health and implications for crop productivity3. Assessment of the risks in the future (20-100 years) accounting for changes in land use, climate and associated changes in application rates of sludges and TWWThe second phase of the Fellowship will use the science platform created during the first phase to investigate the impact of a wider range of ECs that have the potential limit agricultural productivity such as nanomaterials and plastics as well as exploring solutions to mitigate against observed effects. Application of wastewater by-products to land is an accepted practice in a number of countries where populations have a relatively high use of pharmaceuticals (e.g Israel, Southern Europe, Southwest US). Pharmaceuticals have been identified in soils receiving sludges and TWW, and coupled with a recent drive to increase the use of TWW for agricultural irrigation in countries experiencing water shortages, there is an urgent need to establish the global risks of these chemicals in our agricultural systems. Whilst the UK does not currently use TWW for agricultural irrigation, the Environment Agency has suggested there will be significant water supply deficits in the UK by the 2050s. TWW may therefore offer a means of supplementing our demand for freshwater irrigation; however, this solution must be evaluated to ensure environmentally safe protocols are established which promote agricultural sustainability. Outputs of this research will also provide effective evidence for use by non-academic end users (e.g. environmental regulators, water industry, agricultural sector), guiding post-Brexit TWW reuse policies to ensure the UK maintains a world-leading position on mitigating risks of ECs in the environment whilst maximising sustainable reuse.