Soil reference materials (RMs) are critical to ensuring the accuracy and consistency of analytical results across laboratories and research institutions. BGS has produced ten new soil RMs, which have been developed by its inorganic geochemistry team to offer a cost-effective alternative to traditional certified reference materials (CRMs), while maintaining confidence in analytical data. The RMs have been released at a lower price point to help improve access to high-quality materials for researchers and laboratories with limited budgets, enabling them to enhance measurement controls and increase confidence in analytical results across a variety of sectors worldwide. 

Developed from a broad selection of parent materials and incorporating a diverse range of textures and organic carbon contents, reference soils BGS110 to BGS119 have each been characterised by a select group of international laboratories using a variety of analytical techniques. The RMs are also accompanied by data sheets that include for 64 major, minor and trace elements, including rarely measured bromine and iodine. More information about the ten new RMs can also be found in the new report, .

Reference materials are the backbone of geochemical analysis, providing confidence in the measurements that a laboratory produces. Our RMs offer reliable benchmarks for analysing samples with similar matrices. Due to their diverse concentrations of economically and environmentally significant elements, these RMs will enable laboratories, PhDÌýresearchers and industry professionals to calibrate instruments, validate analytical methods and ensure data comparability across studies.

Dr Michael Watts, head of BGS Inorganic Geochemistry.

51ÁÔÆæ now has 18 soil RMs (including one for use in and seven for the analysis of ) and five mineral RMs available for purchase through its website.

The inorganic geochemistry team also remains actively engaged in global initiatives to harmonise soil analytical data across laboratories. These efforts support enhanced health outcomes and food security worldwide. BGS produces custom proficiency testing (PT) materials for international PT schemes coordinated by the Food and Agriculture Organization of the United Nations’ (GLOSOLAN). As part of its collaboration with the FAO-UN and other organisations, BGS has delivered laboratory training around the world, including guidance on producing RMs and PT samples. A free, publicly available is accessible via the GLOSOLAN website.

In addition, BGS prepares geological PT samples and CRMs for a number of commercial distributors, supporting both UK and international PT schemes.

To place an order or for more information on our bespoke RM and PT preparation services, please contact the inorganic geochemistry team (inorganicgeochemistry@bgs.ac.uk). (Gamma irradiated soil RMs are available on request for shipping internationally.)

The University of Nottingham has appointed BGS senior isotope research geochemist, Angela Lamb, as an honorary professor. As part of her role, Angela will contribute to undergraduate and postgraduate teaching alongside facilitating collaborative research programmes between BGS and the University of Nottingham.

Angela research focuses on the application of light stable isotopes to science-based archaeology, palaeoecology and environmental tracing, specialising in sulfur isotopes. She has developed a long-standing collaborative relationship with the University of Nottingham Department of Classics and Archaeology through the jointly operated Centre for Environmental Geochemistry. The centre focuses on the collaborative use of geochemistry in research, training and teaching, investigating:

• environmental and climate change
• biogeochemical cycling, including pollution typing and provenance
• science-based archaeology
• the use of geochemical tools for research into the subsurface

I’m thrilled to have been appointed as an honorary professor at the University of Nottingham and look forward to continuing to build on the legacy of shared research we have developed through the Centre for Environmental Geochemistry. This has already resulted in significant advances in the fields of bioarchaeology, palaeoecology and environmental archaeology.

Prof Angela Lamb, senior isotope research geochemist, BGS.

We’re delighted to welcome Angela Lamb as an honorary professor in the department. We have had a long and productive relationship with Prof Lamb and very much look forward to this continuing in the future. We are particularly excited to develop our work in dietary stable isotope analyses, which help us to understand what people and other animals ate and how societies functioned in the past.

Prof Hannah O’Regan, professor of archaeology and palaeoecology, University of Nottingham.

Pesticide pollution can be extremely damaging to the environment. Pesticides are intrinsically toxic chemicals capable of inflicting a wide range of effects on wildlife, which can in turn cause lasting damage to wildlife populations and ecosystems. Despite these concerns, more research needs to be undertaken to understand the level of pesticide pollution in English rivers.

New research has assessed the , which are currently on the market and being used in various applications, including agriculture. The research also evaluated the pollution by such pesticides in the waters and sediments of two English rivers; the River Tone in Somerset, which runs through Taunton, and the River Wensum in Norfolk, which runs through Norwich. The data generated by the study represents one of the most comprehensive assessments of pesticides in any English river catchment to date and is widely applicable to other river catchments across the UK.

Water, sediments, fish and invertebrates were collected along the two rivers and analysed for 52 pesticides. The study, undertaken by BGS in collaboration with the University of Nottingham, found that the veterinary pesticide fipronil was measured at high concentrations. Fipronil is commonly used by vets as an anti-flea treatment for dogs and likely gets into our rivers by dogs accessing these waterways. In addition, propiconazole (a systemic fungicide commonly used in agriculture) was found at elevated concentrations in sediments from the rivers Tone and Wensum.

Neonicotinoids, a group of neuro-active insecticides, are used in agriculture to help prevent crops from being eaten by pests and were found in both of the rivers. At one-third of the sites sampled, the level of neonicotinoids exceeded the chronic threshold for aquatic invertebrates, meaning they will be affecting the health of these organisms.

Modern chemical pesticides have positive applications, such as veterinary medicines helping prevent fleas in domestic pets and in UK agriculture where herbicides, insecticides and fungicides can help prevent food shortages by protecting crops from various pests.

However, our research has highlighted that these pesticides are now present in English rivers and could potentially pose threats to the local wildlife. To help mitigate the risk to ecosystem health, additional protective measures are needed to promote more environmentally sustainable practices, alongside the introduction of stricter regulation around the most high-risk pesticides to help protect our rivers from further impact.

Christopher Vane, head of BGS Organic Geochemistry.

The research has highlighted that further studies need to be completed in order to determine the effects that modern pesticides could have on ecosystems of rivers. BGS will also complete additional research in other countries over the next few years, which will continue to assess which pesticides are present in rivers.

The research paper, ‘, is available to read.

They presented their findings at a stakeholder workshop in Kisumu at the Kenya Marine Fisheries Research Institute (KMFRI). Stakeholders were gathered from academia, research institutes and government, along with community representatives and they were all invited to share their experiences in land and lake management.ÌýÌý

Changes to Kenyan land-management practices are urgently needed for sustainable agricultural productivity and to reduce the growing problem of soil erosion and transfers into Lake Victoria, which compromise the growing economic and food security dependence on fisheries aquaculture. The goal of the workshop was to find a way to better coordinate disparate research and create partnerships to improve communications that will better inform land-management decision makers. 

The workshop 

The workshop covered three exercises across three groups, with the first two set up as ice breakers and to help participants consider how they could translate research findings into impact. These exercises directed discussion towards the preparation of policy briefs: what they are, who reads them and how they can be effective, alongside examples of community engagement to change behaviour or practice.  

The third exercise generated the most discussion on how data and research should be coordinated and shared, with examples of good practice being quite rare owing to a lack of resources and expertise. Additionally, the exercise discussed whether there could be a process to enforce the delivery of research harmonisation, improved reliability of data quality and the ability to consider multiple research outcomes from numerous projects. Again, examples of good practice were limited, although less direct means of communication to policy decision makers were discussed; for example, via media or a community bottom-up approach.Ìý

Overall, the workshop demonstrated that the key to enabling a positive change in behaviour and practice for land and lake management is ensuring community engagement from the outset of a research project, such as engaging with focus groups, having community representatives or enabling citizen science participation. The workshop participants agreed that a committee was essential to share research outputs with relevant stakeholders in the Lake Victoria basin. A virtual platform is also essential to a functional framework, so that research outcomes are better shared, data is used in multiple ways to realise efficiency gains and long-lasting impact is created from research. However, such a platform would require adequate resourcing and continued support from stakeholders, alongside engagement from policy decision makers.  

Joint research with the University of Eldoret and KMFRI 

Research shared with this group was funded via previous Royal Society and NERC grants. It initially involved mapping the geochemistry across the Winam Gulf catchment of the Lake Victoria basin, to model the areas at greatest risk of soil erosion and identify more precisely the locations within a river catchment suitable for targeting limited resources to train farmers and test intervention methods to reduce soil erosion.  

Secondly, sediments and sediment cores were surveyed across the Winam Gulf catchment, to generate a chronology of sediment run-off over the past 100 years, as well as the extent of metal and nutrient land-to-lake transfers. This will help us to better understand the effects of poor land management on the lake environment.  

Field collections, measurements, and digitisation and modelling of data were described in previous blogs, with partnerships cemented by the exchange of technicians, early career researchers and principal researchers. The opportunities created by this collaborative project collectively and individually demonstrate the potential for scientific research to address environmental issues whilst developing scientific capacity in Kenya and the UK. The two-way exchange of staff and paired UK/Kenya PhD students provided an enriching experience for all involved. 

Continuing partnerships  

Ongoing efforts will see improvements to modelling the risk associated with soil erosion, including translating a machine-learning model for predicting risk at the sub-catchment scale to other similar land-lake environments, to determine changes in soil losses/sediment transfer at historical scales (100 years) and through dynamic modelling (within few years). Funding to support an advisory forum for Lake Victoria has the potential to set a template for the region on how to better coordinate research data. This will be of particular value to developments in machine learning, which can analyse vast amounts of data quickly. Machine learning could provide a broader, more effective perspective beyond the typical scope of a research project but is dependent on harmonised approaches to data capture and quality. 

Data and information are very expensive due to their endless nature and the value attached to them; thus, quality collaboration between KMFRI, BGS and UoE has created a unique platform to provide baseline and useful data and information on lake-land interphase, which will form the foundation of lake-basin management, planning and conservation in the region. 

Data and information are very expensive due to their endless nature and the value attached to them; thus, quality collaboration between KMFRI, BGS and UoE has created a unique platform to provide baseline and useful data and information on lake-land interphase, which will form the foundation of lake-basin management, planning and conservation in the region. 

Acknowledgements 

We would like to thank: 

• Olivier Humphrey and Andy Marriot, who provided expertise in machine learning, and sampling strategy and fisheries, respectively (BGS)Ìý

• Job Isaboke and Sophia Dowell, joint UK/Kenya PhD studentsÌý

• Staff from all three institutes that supported laboratory and field work, logistical arrangements and community engagementÌý

• Collins Ongore, Job Mwamburi and George Basweti (KMFRI)ÌýÌý

• Elliott Hamilton and Amanda Gardner (BGS)Ìý

• Prof William Blake for guidance on soil erosion sampling strategy and translation of data outcomes into useful data tools to advise on land management (University of Plymouth).Ìý

Funding 

This work was financially supported by:  

• Natural Environment Research Council (grant numbers NE/R000069/1, NE/X006255/1, NE/S007334/1 and GA/19S/017)Ìý

• Royal Society (grant number ICA/R1/191077])Ìý

• British Academy (grant number WW21100104] )Ìý

• Commonwealth Scholarship Council UK for professional fellowshipsÌýÌý

About the authors 

Dr Christopher M Aura: Director of Freshwater Research at the Kenya Marine Fisheries Research Institute. Chris was a co-PI on the joint research, with oversight on the lake management, sampling and community engagement. 

Prof. Odipo Osano: Professor of Environmental Sciences at the University of Eldoret.  Odipo was a co-PI on the joint research, with oversight on the land sampling and community engagement, overall coordination of Kenyan activities. 

Dr Michael Watts: Head of Inorganic Geochemistry and Lead for International Geoscience R&D at BGS.  Michael was the PI for UK funded grants and overall coordinator for the project. 

The 51ÁÔÆæ Inorganic Geochemistry Facility (IGF) provides high-quality analytical expertise and specialist services for the production and interpretation of inorganic geochemistry data for commercial, academic and public sector clients worldwide. This year marks the facility 25th ±õ³§°¿/±õ·¡°ä 17025 accreditation, a gold standard that fosters trust in the quality of the facility work.  

What is ISO/IEC accreditation? 

This accreditation is the formal recognition by the UK Accreditation Service (UKAS) that an organisation meets the specific requirements of a standard; in our case, . Our accreditation ensures that all staff operate according to internationally recognised standards, underpinning our credibility, impartiality and confidentiality, whilst instilling confidence in our customers that the services provided by BGS conform to the highest quality. 

Fundamentally, it is the core quality system framework and its management that is accredited, ensuring that all analytical techniques are performed under the same quality assurance requirements. The technical scope of accreditation has evolved over the years, adapting to changes in demand and availability, and currently includes the determination of cation, anion and aqueous parameter concentrations in natural and experimental water samples. 

Maintaining accreditation for 25 years highlights the commitment and consistency of high-quality outputs of the IGF and its staff.  

How it all started 

In August 1999, the then BGS Analytical Geochemistry Laboratory was awarded ±õ³§°¿/±õ·¡°ä 17025 accreditation by UKAS, making the laboratory one of the very few organisations within the UK research community to hold UKAS accreditation at that time. The initial drive to acquire accredited status came from working on samples provided by the Nuclear Industry Radioactive Waste Executive (NIREX), as robust quality assurance was essential for the project. This requirement essentially established the working practices from which the laboratory was able to derive its management system. The work for NIREX heightened the laboratory staff’s appreciation of the benefits of having a comprehensive management system, so it was simply a case of taking small steps to gain formal recognition against ISO/IEC 17025.  

As BGS provides global public-good science and work for commissioning bodies and legislators, it is of paramount importance that we can provide credible, impartial data. The accreditation status of the IGF has proved instrumental in receiving long-term, large-scale projects and will continue to do so where credibility and confidence in results are of the utmost importance. 

What does it mean for BGS? 

The IGF conducts internal audits on all activities as well as having independent experts from UKAS carry out an external audit on an annual basis. Overall, the culture in an ISO/IEC 17025-accredited facility is one of professionalism, accountability and a commitment to excellence, creating an environment that supports high-quality data outcomes used by academics and industry.  

51ÁÔÆæ has always been highly regarded in the geoscience community and we often set the standard on how to conduct research. Accreditation to an international standard provides formal recognition to wider industry and the UKAS accreditation is a key part of the IGF identity, instilling a culture that emphasises quality, reliability and continuous improvement. This strong focus on quality at all stages is one of our key strengths and all members of the team understand and adhere to protocols to ensure compliance and the production of high-quality outputs. The culture of continuous improvement encourages feedback and ensures processes are regularly reviewed and updated. 

The accredited status of the IGF has significantly contributed to overseas science partnerships, facilitated BGS-hosted training of laboratory technicians and enhanced capacity-strengthening projects across the globe including Afghanistan, Kenya, Kyrgyzstan, Nigeria, Liberia, Malawi, Saudi Arabia, Tajikistan, Zambia and Zimbabwe.  

Due to our accreditation status, the IGF is a highly sought-after industry placement for undergraduate chemistry students who want to specialise in environmental chemistry. The 12-month industry placement we offer to students from the UK, New Zealand/Aotearoa and Australia equips them with the skills they need to excel in both academic and commercial workplaces, with many of the students going on to work in other accredited laboratories and highly regulated industries. Read more about the success of previous students.  

How will it continue to be relevant in the future? 

The IGF accreditation against ±õ³§°¿/±õ·¡°ä 17025 demonstrates our ongoing commitment to quality assurance, the reliability of results and regulatory compliance, which is crucial for environmental monitoring. The IGF remains adaptable to ensure we can meet future requirements and regulations, and maintains a level of preparedness for future, national-scale programmes. 

About the author

Bladder cancer incidence ranks ninth out of all cancers worldwide, with over 600Ìý000 cases and 200Ìý000 deaths annually. In the UK, these numbers are 10Ìý000 and 5000, respectively, with only 46Ìýper cent of patients surviving for around 10 years. Almost half of bladder cancers are diagnosed at stages 3 and 4, with poorer prognosis for these later stages.

The ‘gold standard’ diagnostic procedure for bladder cancer is cystoscopy. As well as being an invasive test involving the insertion of a camera into the bladder, it is more costly in the UK than anywhere else in Europe. Currently, the UK has the third-highest bladder cancer healthcare costs per prevalent case in the world.

A research team that includes chemical analysts from BGS has been awarded a grant from Cancer Research UK to test the performance of a urine-based liquid biopsy test for the disease. To date, due to their poor performance and low cost-effectiveness, commercially available urine biomarkers have not been recommended by urological societies for the screening or management of bladder cancer.

The new test, which works by searching for genetic mutations known to occur in a large proportion of bladder cancers, was initially developed under the leadership of Dr Florence Le Calvez-Kelm at the . It has already shown early success in the accuracy of detecting the disease in European populations. In this new research project, called ‘UroScan’, the team will look at 100 bladder cancer cases and the same number of healthy controls, who will all undergo the test to assess its accuracy.

This is the first time the test will be used in a population at high risk of arsenic exposure in Bangladesh. Arsenic is an established bladder carcinogen and affects people in the UK as well, particularly those using an untreated private drinking water supply. Participants’ urine samples will undergo arsenic measurement by Dr Michael Watts and his team of analytical chemists at BGS.

The development of accurate, non-invasive early detection methods are a critical step to reducing bladder cancer burden and diagnostic waiting times, particularly when considered against pre- and post-pandemic pressures on the NHS and its growing backlog of cancer patients.

Dr Dan Middleton, Cancer Epidemiology Group, Centre for Public Health at Queen University Belfast.

Investigating the potential of early detection biomarkers for bladder cancer in an understudied population of Bangladesh is pivotal in the context of reducing the burden of cancer in this region and beyond.

Dr Ismail Hosen, University of Dhaka, joint lead researcher.

This project builds on a collaboration of more than 10 years of refining the methodologies to better understand the potential exposure to arsenic in the environment and to inform the consequences for human health to stimulate approaches to reduce exposure.

Dr Michael Watts, head of BGS Inorganic Geochemistry.

The researchers have recently started the study and the first results are expected in 2025, before hopefully scaling up to a larger, UK population-based study that will incorporate exposure to arsenic in highly mineralised locations in rural areas, where private water supplies are most common.

My name is Paulina Baranowska and I’m a second year PhD student. My project is hosted at BGS, in collaboration with the University of Nottingham and funded by AWE.

Project aims

The aim of my PhD project is to advance nuclear forensic science by investigating the use of oxygen isotopes as a nuclear forensic signature, and to develop a novel technique to measure the oxygen composition of nuclear materials. I am using surface-science techniques to understand the impact of corrosion and exposure to varying environmental conditions on nuclear materials, and the influence this has on the oxygen isotope signature.

Surface-science techniques are valuable tools for assessing the effect of corrosion on materials and include:

• scanning electron microscopy (SEM)
• X-ray diffraction (XRD)
• X-ray photoelectron spectroscopy (XPS)
• thermogravimetric analysis (TGA)

Together, these techniques can provide a complete picture of how environmental changes affect both the surface and bulk of a studied material, and enhance our understanding of the forensic signatures incorporated by these materials. This understanding enables us to determine their origin and history more precisely.

The project also aims to obtain a better understanding of how to design appropriate methods for oxygen isotope analysis using various analytical techniques. This research represents a novel and interdisciplinary approach to nuclear forensics that combines surface-science chemistry, material behaviour and stable-isotope geochemistry.

What is nuclear forensic science?

Nuclear forensic science focuses on the examination and identification of evidence to support governments in managing incidents involving nuclear and other radioactive materials ‘out of regulatory control’. This means incidents where nuclear or radioactive materials are not under prescribed regulatory oversight, supervision, or legal constraints, posing potential risks due to unauthorised possession, use or transfer.  

A wide range of forensic signatures is used to assess the origin of materials and inform law enforcement for further investigation​​. The production route of a trafficked or lost material, including where, when and how the material was produced, can be found using various analytical techniques.

The role of oxygen isotopes

Using the oxygen isotope composition of materials for nuclear forensic purposes is a new and novel approach. Oxygen isotopes have been used as an environmental tracer for the past 70 years, as the balance of oxygen isotopes in natural materials is influenced by the prevailing climate and surrounding environment, including factors such as temperature, humidity and the source of water. This can provide insight into the geographical origin of materials or the conditions they have been exposed to, which is highly valuable to forensic investigations.

As natural materials form, they capture the oxygen isotope composition of the surrounding environment at the time of their formation, which is the basis of palaeoclimate research and environmental change reconstructions. However, this is also true for conditions and processes in modern environmental settings, including corrosion processes.

Corrosion involves a gradual deterioration of metal surfaces via a chemical reaction to reach a more chemically stable form (for example, oxidation of a metal to an oxide or hydroxide). The incorporation of a specific oxygen isotope composition in a corrosion product will reflect the ambient and geographic conditions that it formed under, providing a distinctive oxygen isotope signature that can be analysed to trace the material exposure history. Oxygen isotopes can therefore potentially be used as a forensic tracer to differentiate between different geographical origins of nuclear materials. Ultimately, this can help narrow down the source of an unknown material in a forensic investigation. 

Current analytical constraints limit the use of oxygen isotopes in nuclear forensic research, particularly in the context of uranium compound analysis. Classical and laser fluorination methods, commonly used for oxygen isotope analysis, suffer from limitations such as low sample throughput, low efficiency, large sample mass and the high risk associated with using the chemical reagents required to liberate the oxygen.

Given these challenges, elemental analyser-isotope ratio mass spectrometry (EA-IRMS) is considered an alternative option. My work aims to develop an automated method of analysing heavy metal oxides using EA-IRMS. The method combines surface-science techniques with isotope geochemistry to understand controls on the oxygen isotope composition in heavy metal oxides to assess the forensic signatures and the use of oxygen isotopes as a nuclear forensic tracer.

About the author

Paulina started her PhD after completing an MChem degree at Nottingham Trent University. Her master project focused on the analysis of radioactive elements in cosmetics from the 20th century, sparking her interest in radiochemistry. Prior to beginning her PhD, Paulina had the opportunity to work as a technician in a university laboratory, which reinforced her desire to work within analytical and nuclear chemistry and encouraged her to seek out a PhD project that combined these areas of science.

My name is Maureene Auma Ondayo and I am a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. In this blog I will share my PhD research, investigating major and trace element exposure in the environment. This includes ores, soils, sediment and waters, locally grown staple food crops (maize, leafy vegetables, pulses and tubers), and human samples (hair, nails and urine). My research also incorporates risk factors of exposure to potentially harmful elements (PHEs) and associated health implications among artisanal and small-scale gold mining workers and local residents.  

What is artisanal and small-scale gold mining?  

Artisanal and small-scale gold mining (ASGM) is an informal mining sector that provides subsistence-level livelihoods for many rural communities across the world. In Kenya, ASGM occurs in Migori, Narok, Siaya, Vihiga, Kakamega, Nandi, Kisumu, Turkana, West Pokot, Marsabit, Homa Bay and Kericho counties. It is estimated that ASGM production yields around 5 metric tons per year (worth around £250 million), employing 250 000 workers with more than 1 million dependents. The main environmental and health risks associated with ASGM relate to poor conditions at mining camps and mining operations, which include the extensive misuse of mercury in the production process.   

Mining the gold 

Miners often rely on local knowledge when prospecting for gold after which agricultural land and pristine forests are cleared to make way for the mine. Ores are excavated and broken into smaller pieces using sledgehammers and mills, dispersing large volumes of contaminated dust across nearby environments and communities. Milled ore powder is then wetted and sluiced to extract the gold particles. Panning separates gold-associated sediment particles, then liquid mercury is added, which joins together with the gold to form an amalgam and separates it from the sediment. The amalgam is then burnt on open flames, vaporising the mercury and leaving behind the gold, whilst tailings and wastewater from ASGM are disposed of in nearby farms, residences, playgrounds and waterways. 

These activities expose the workers and local populations to extreme health and safety hazards, with injuries, diseases and premature deaths reported in ASGM areas.  

Hazards of ASGM 

Exposure to potentially toxic elements (PTEs), physical hazards, gaseous emissions, overexertion, physical injuries and poor ventilation inside the mines are the key hazards to human health in ASGM. This exposure results in a wide range of health disorders including:  

• cancers 
• immunity suppression 
• neurological disorders 
• developmental health effects  

Socio-economic issues related to mining activities are also present in local areas, including alcohol and addiction, violence and HIV/AIDs.  

My research 

During my PhD, I investigated the environmental and human exposure and health implications among nineteen ASGM communities in Kakamega and Vihiga counties, Kenya. 

I collected soil, sediment, water, locally grown food and human biomarker samples (hair, nails and urine) from ASGM workers and residents of ASGM villages and analysed them for major and trace elements at BGS Inorganic Geochemistry Facility in Keyworth. Further risk factors from PTE exposure and potential health effects among the studied ASGM communities were assessed through interviews.  

Study results 

Kakamega and Vihiga counties are naturally enriched with macro- and micro-elements and the ASGM activities primarily disperse them across surrounding environments and communities. The results show that:  

• soils, sediments and water sources in the ASGM villages were highly polluted by PTEs, including arsenic, mercury, chromium, lead and nickel 
• soil concentrations of arsenic, chromium and nickel in the studied ASGM villages were 154, 9 and 4 times higher than background concentrations, respectively 
• drinking-water samples in the ASGM villages, including springs, shallow wells and mine shafts, were heavily polluted with arsenic, lead and chromium. Very worryingly, we observed mine workers and residents drinking mine-shaft water, the most contaminated water at the ASGMs, when they were extracting the ore!  
• locally grown staple food crops were also contaminated with arsenic, nickel, lead, chromium, cadmium, mercury and aluminium, and were not considered safe for consumption  

The inhalation of gaseous PHEs like mercury during amalgam burning, the consumption of locally grown staple food crops and drinking water, and ingesting PTE-contaminated dust and soils (especially children and pregnant women that exhibit pica, that is, eating non-food items like soil) were the main exposure pathways found in our study. Self-reported potential pollution-related health effects included cancers, neurological effects, respiratory infections, musculoskeletal effects, infectious diseases including HIV/AIDS, and malaria.    

Working with the ASGM community 

A key aspect of my PhD was the multidisciplinary research approach taken to understand the relationships between the environment, diet and public health to effectively assess and communicate human exposure and health risks. We continue to collaborate with ASGM workers, local communities and local health practitioners while sharing our findings.  

On 2 December 2023, we met with county public health administrators to understand how best to present and share the data for interpretation with our key stakeholders. These include: 

• politicians 
• broader county employees 
• the departments of mining, environment, and law enforcement 
• community health workers 
•  the studied ASGM communities in both Kakamega and Vihiga counties 

Additional meetings with public health officers, medical practitioners, environment and agricultural departments and other key stakeholders are planned. This will let us share our results and recommendations on reducing PTE exposure through environmental, occupational and public health safety controls, such as: 

• providing safer drinking water to ASGM communities 
• relocating residences and schools away from ASGM activities  
• controlling dust transfer 
• encouraging regular personal protective equipment (PPE) use 
• alternatives to mercury 
• safer cyanidation operations 
• wet milling 
• technological interventions in ore exploration, excavation, processing and recovery 
• targeted education and training on industrial hygiene 
• public health policy formulation in ASGM in Kenya 

This study characterised PHE exposure pathways and health risks among ASGM communities in the Kakamega gold belt. Our findings are valuable to public health authorities as they inform them of the mitigation actions that are needed to research further, reduce exposure, improve ASGM processes, and protect the environment, food sources and the health of ASGM workers and residents, including policy formulation. 

About the author 

Maureene Auma Ondayo is a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. 

Co-authors  

Prof Odipo Osano is an environmental toxicologist at the University of Eldoret, Kenya. He has a background in veterinary medicine, public health, and community and laboratory-based environmental epidemiological research.   

Clive Mitchell, BGS Industrial Minerals Geologist.   

Dr Olivier Humphrey, BGS Environmental Chemist.   

Dr Michael Watts, BGS Head of Inorganic Geochemistry and lead for BGS International Geoscience Research and Development.