Air-quality networks collect environmental DNA with the potential to measure biodiversity at continental scales.

One of the biggest planetary challenges is the accelerating loss of biodiversity threatening ecosystem functioning on a global scale. The WWF Living Planet Report (https://livingplanet.panda.org/) estimates a 69% decline in populations since 1970. The Convention on Biological Diversity and related international treaties ask countries to monitor shifts in community composition and assess rates of species decline to quantify extant biodiversity relative to global targets1. However, quantifying biodiversity is a challenge, and monitoring continual change is impossible at almost any scale due to a lack of standardized data and indicators2,3. A common problem is that the required infrastructure for such global monitoring does not exist. Here, we challenge this notion by analysing environmental DNA (eDNA) captured along with particulate matter by routine ambient air quality monitoring stations in the UK. In our samples, we identified eDNA from >180 vertebrate, arthropod, plant and fungal taxa representative of local biodiversity. We contend that air monitoring networks are in fact gathering eDNA data reflecting local biodiversity on a continental scale, as a result of their routine function. In some regions, air quality samples are stored for decades, presenting the potential for high resolution biodiversity time series. With minimal modification of current protocols, this material provides the best opportunity to date for detailed monitoring of terrestrial biodiversity using an existing, replicated transnational design and it is already in operation.

Falling nickel concentrations in ambient air in South Wales - 50 years of progress.

Measurement of the composition of ambient air has become increasingly widespread over the last 50 years as the detrimental health effects of some air pollutants have become clearer and requirements for these measurements has been embedded in national and international legislation. The aim of this has been not only to assess exposure of the general population to air pollutants but also to assess the effectiveness of abatement strategies to reduce emissions of these pollutants at source. With a rich industrial heritage, the Swansea Valley (South Wales, UK) has long been associated with the refining and production of metal products, especially nickel. Despite a decline in output during the latter part of the twentieth century there is still sufficient activity to prompt a requirement for targeted air monitoring in the area. This is most important for nickel where there is a local history of measured concentrations exceeding legislative target values. This work demonstrates the effectiveness of nickel emissions abatement strategies over the last 50 years by tracking the falling air concentration of nickel over this period. It also demonstrates how the monitoring network in the Swansea Valley has expanded over this time and become significantly more sensitive to nickel emissions. The data presented represents a significant public health achievement - it is likely that the exposure to nickel in air of the population in the Swansea Valley has decreased more than 100-fold over the last 50 years - and reflects the progress in regulation, industrial efficiency, emissions abatement technology and air quality monitoring science achieved during this period.

Concentration trends of metals in ambient air in the UK: a review.

The monitoring of metals in ambient air has been undertaken for over 40 years on a national basis in the UK. During this period, the UK pollution landscape has continued to evolve in terms of emission sources, and the measurement framework for metals in ambient air, the UK Heavy Metals Monitoring Network, has also been subject to significant configuration changes. Therefore, this work provides a timely review of more recent concentration trends in the context of current emission profiles. Overall, throughout this time period, there has been a significant downward trend in the emissions and consequently, the measured concentrations of most metals in UK ambient air. Ambient concentrations were generally found to be well correlated with emission estimates. Analysis of the sensitivity of measured concentrations to emissions suggests that concentrations have fallen faster than the reduction in emission estimates would have predicted at typical median urban background sites.