Environmental Medicine and Clinical Practice: The Role of Toxicant and Non-ionising Electromagnetic Field Exposure on Health Outcomes and the Ramifications for Clinical Practice

Human exposure to environmental chemicals (toxicants) and non-ionising radiation electromagnetic fields (NIR-EMFs) has increased exponentially over the past four decades and a growing body of evidence suggests these exposures contribute to many chronic diseases typically seen in clinical practice. There are various complexities involved in investigating these exposures and it is unclear how clinicians recognise and assess these exposures, or the barriers and challenges they face incorporating environmental medicine into clinical practice. The research approach of this thesis was a combination of two literature reviews, qualitative study, and a randomised controlled trial. The literature review revealed population-wide exposures to toxicants are ubiquitous, and the body burden is increasing with each generation. Toxicant exposures account for a significant portion of cancer mortality worldwide as well as neurodevelopmental, neurodegenerative, reproductive and autoimmune issues, along with respiratory and cardiovascular diseases. These exposures are disproportionately distributed among different social classes and races, and toxicant exposures during critical periods of development have been shown to have lasting effects that span generations. In addition, exposure to man-made NIR-EMFs is widespread, yet difficult to study and have been linked to sleep disturbances, childhood leukaemia and brain tumours. This escalation in environmental exposures has occurred concomitantly with an upsurge in the occurrence of patients presenting with chronic and multimorbid conditions. A review of the literature revealed sleep disturbances has become a significant public health issue, and this has coincided with the widespread deployment of wireless technologies. In order to further investigate the impact of wireless technologies on sleep, a randomised controlled trial was conducted to investigate the impact of multi-night exposure to a 2.45 GHz device (baby monitor) on subjective and objective sleep parameters under real-world conditions. Compared to sham exposure, RF-EMF exposure resulted in a statistically significant and clinically meaningful reduction in sleep quality as indicated by the PIRS-20 scores (p<0.05) and a statistically significant increase in EEG power density in the higher frequencies (beta, gamma and theta bands) during Non-Rapid Eye Movement (NREM) sleep (p<0.05). No statistically significant differences were observed in heart rate variability or actigraphy. Risk assessment, setting of exposure standards and the regulation of toxicants and NIR-EMFs is inadequate. There are challenges in establishing a causal relationship between exposure and outcomes due to factors that include: multiple routes of exposure, complex mixtures, non-monotonic dose-responses, transgenerational epigenetic effects and identifying susceptible populations. Additionally, there is a lack of standardised tools to assess the quality of toxicological studies, hindering the evaluation of health risks associated with chronic, low-level exposure to chemicals over a lifetime. Similarly, in the field of EMF research, despite decades of research, most studies display methodological weaknesses that limit the internal validity of the results. Furthermore heterogeneity between studies makes it difficult to compare or collate results and most systematic reviews are unable to draw firm conclusions. While advancements in science, particularly in the omics fields, have provided valuable insights into the complex interplay between genetics and various risk factors over the course of a person’s lifetime, risk assessment could be vastly improved for example, by grouping chemicals into classes to facilitate timely protection and prevent regrettable substitutions. Furthermore the regulation of NIR-EMFs needs to account for non-thermal effects, reflect real-world conditions and be conducted over longer periods of time taking into consideration the totality of exposure using personal monitoring devices and mapped to health effects (Apps). Methodologies could also consider exposure dosimetry, placement of exposure devices that are well-defined, consistent, and consider signal features such as modulation, field strength, resonance, pulsing, polarisation and power flux density. Health care systems have fallen short in their ability to translate knowledge into practice due to challenges accounting for individual differences; determining the strength of evidence and probability of causation, especially when the evidence is inconclusive; and managing conflicts of interest. The absence of public health policy and clinical guidelines and consequent lack of actionable outcomes, often lead to uncertainty in the diagnosis and treatment of patients impacted by environmental exposures. Consequently, despite the call for regulatory reform and the need for training on environmental medicine from numerous stakeholders, environmental assessment is generally overlooked in clinical practice and is largely ignored. The field of environmental medicine is without rigorous definition and is not integrated into general medical practice. To further explore the complexities and barriers to assessing environmental exposures in clinical practice, a qualitative study was undertaken involving a series of in-depth, semi-structured interviews with clinicians who were members of professional environmental medical organisations. The interviews were recorded and transcribed, and the data was analysed using NVivo 11.3 software to identify dominant themes across the cohort. Whilst clinicians face numerous challenges in assessing environmental exposures due to limited educational resources, lack of definitive laboratory tests, and inadequate training, they agreed that an environmental exposure history is the most valuable clinical tool. Despite extensive postgraduate education and clinical experience, few practitioners consider themselves experts in this field. Overall the outcomes of this thesis suggests there is a need to publish environmental health research in clinically-related medical journals with actionable outcomes. It is also proposed that environmental health research be incorporated into undergraduate medical training to equip clinicians with the skills to identify patients impacted by exposures, and that Environmental Medicine be established as a medical speciality that involves postgraduate medical training incorporating a personalised medicine approach. This may involve undertaking comprehensive exposure histories (obstetrics, paediatrics, dietary, dental, occupational, trauma, lifestyle and environmental), utilising nutritional and genetic testing, as well as tests to measure toxic load that incorporate ‘omics’ technologies. It is further proposed that educational resources and targeted campaigns be disseminated by health authorities to the public, advising on potential risks of toxicants and NIR-EMFs so that consumers can make an informed choice. By better understanding the relationship between environmental exposures and health outcomes for current and future generations, clinical environmental risk assessment can pave the way for a new era of personalised medicine that unites healthcare professionals, patients, and civil society in exploring the links between the environment and human health. nicole<p></p>