School of Science, Engineering and Environment, University of Salford, Salford, UK.
UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Bailrigg, UK.
J Anim Ecol. 2022 Jul;91(7):1546-1553. doi: 10.1111/1365-2656.13743. Epub 2022 Jun 13.
Anthropogenic releases of radiation are of ongoing importance for environmental protection, but the radiation doses at which natural systems begin to show effects are controversial. More certainty is required in this area to achieve optimal regulation for radioactive substances. We recently carried out a large survey (268 sampled animals and 20 sites) of the association between environmental radiation exposures and small mammal gut-associated microbiomes (fungal and bacterial) in the Chornobyl Exclusion zone (CEZ). Using individual measurements of total absorbed dose rates and a study design and analyses that accounted for spatial non-independence, we found no, or only limited, association. Watts et al. have criticised our study: for not filtering candidate non-resident components prior to our fungal microbiome analyses, for our qualified speculations on the relative merits of faecal and gut samples, and for the design of our study which they felt lacked sufficient replication. The advantage of filtering non-resident-fungal taxa is not clear and it would not have changed the null (spatially adjusted) association we found between radioactive dose and mycobiome composition because the most discriminatory fungal taxa with regard to dose were non-resident taxa. We maintain that it was legitimate for us to make qualified discussion comments on the differences in results between our faecal and gut microbiome analyses and on the relative merits of these sample types. Most importantly, the criticism of our study design by Watts et al. and the designs and analysis of their recent studies in the CEZ show a misunderstanding of the true nature of independent replication in field studies. Recognising the importance of spatial non-independence is essential in the design and analysis of radioecological field surveys.
人为辐射释放对环境保护具有持续的重要性，但自然系统开始出现影响的辐射剂量存在争议。在这方面需要更多的确定性，以实现对放射性物质的最佳监管。我们最近在切尔诺贝利禁区（CEZ）进行了一项大型调查（268 个采样动物和 20 个地点），研究环境辐射暴露与小型哺乳动物肠道相关微生物组（真菌和细菌）之间的关系。使用个体总吸收剂量率的测量值以及考虑空间非独立性的研究设计和分析，我们没有发现或只有有限的关联。Watts 等人批评了我们的研究：没有在进行真菌微生物组分析之前过滤候选非居民成分，没有对粪便和肠道样本的相对优点进行限定推测，以及他们认为缺乏足够重复的研究设计。过滤非居民真菌类群的优势并不明显，也不会改变我们在放射性剂量和微生物组组成之间发现的零（空间调整）关联，因为与剂量最具区分性的真菌类群是非居民类群。我们认为，我们对粪便和肠道微生物组分析之间结果差异以及这些样本类型的相对优点进行限定讨论是合理的。最重要的是，Watts 等人对我们的研究设计的批评以及他们在 CEZ 进行的最近研究的设计和分析表明，他们对实地研究中独立重复的真正性质存在误解。认识到空间非独立性在放射性生态学实地调查的设计和分析中的重要性至关重要。
