Currently, physicians across the globe receive very little training in environmental risk factors, largely due to the absence of core competencies in educational institutions. With commitment, collaboration and collective effort between international health agencies and educational institutions around the world, physicians could be receiving training in a field that benefits humankind by preventing costly diseases.

Building physician competence in Child Health and the Environment (CHE) concepts would facilitate a comprehensive approach to early identification and mitigation of relevant environmental risk factors in all branches of medicine promoting health not only in children but also in the adults they grow up to be.

Many cultures recognise that the health of children is inherent to the survival of the human race.¹ Therefore, public health measures and social supports were instituted resulting in decreased infant mortality, and increased life expectancy, leading to population growth. In addition, medical science provides astounding diagnostic possibilities and treatments for many disorders. While advances have been made, however, new dangers have arisen.

Global environmental exposures present a serious threat to child health,² and this issue warrants further examination and action. Over 25% of child mortalities below the age of 5 worldwide are attributable to harmful environments.³ The sources of these detrimental environments, such as second-hand smoke and air pollution (indoor and outdoor), and unsafe water, are responsible for 1.7 million deaths in children under 5.³ In addition, many common conditions are on the rise, especially in young people, for example, respiratory disorders, metabolic disorders, neurodevelopmental problems, cardiovascular diseases, hypertension, cancers and obesity.^4–6 Evidence is accumulating that many of these chronic issues are related to environmental exposures during early life.^{6 7}

Many early-life exposures in turn predispose a child to chronic lifelong conditions such as asthma or neurodevelopmental disorders, which significantly impact both the child and community resources. For example, prenatal pesticide exposure is known to negatively impact mental development in children.⁸ The spiral of needs, once initiated, may necessitate costly interventions from healthcare, as well as social programmes such as education and the judicial system. The economic burden on societies from environmentally related health outcomes is also significantly impacted by the loss of productivity throughout life. An analysis by Trasande and colleagues estimated the cost of environmental disease in children 2008 to be US$76.6 billion in the USA.⁹ The authors evaluated the health and lifetime productivity costs associated with childhood lead poisoning, prenatal methylmercury exposure, childhood cancer, asthma, intellectual disability, autism and attention deficit hyperactivity disorder, revealing a significant economic loss that could be improved through efforts to prevent exposures to toxic chemicals.⁹

Modern medicine responds to urgent immediate problems with curative solutions and tends to stumble in the face of seeking and applying proactive preventive measures that could reduce the development of chronic illness.¹⁰ As availability of expensive medical technologies and expertise increases, healthcare costs are escalating. Clinical medicine appears to be on a trajectory to provide ever more cures, a natural response to increasing complaints and diagnoses. In Canada, our laudable healthcare system is struggling to meet the rising demands for clinical care.¹¹ This is certainly reflected in health spending.¹²

Surely a large part of the answer lies in better identifying and addressing causative risk factors for the many conditions that have been described as having an environmental component. Such complex problems require interdisciplinary investigations that inspire novel approaches to preventive strategies. Numerous examples in the scientific literature are alerting us to the significant effects that social, nutritional and chemical factors in early life play on health outcomes not only in childhood but also throughout the entire human lifespan.^13–16 In addition, children are highly susceptible to the health consequences of climate change, including dramatic fluctuations in air quality, extreme weather and infectious disease.¹⁷

The curative model lends itself to evaluation more readily while the preventive one seems more difficult to evaluate. The value of preventive care is broadly recognised; however, it requires long-term vision, while treatment offers rapid gratification to patients, and as a result, it is still often preferred by the public.¹⁸

CHE is an emerging discipline that addresses early life exposures on outcomes throughout a person’s life. It recognises the physical, biological, social and chemical environments as well as their intricate interactions. It considers prenatal and postnatal influences as well as environmental influences on the human genome and transgenerational effects. Central to CHE is the special vulnerability of children through their promise of longevity, unique exposures and dynamic developmental physiology.^19–21

Solving clinical dilemmas in CHE involves identifying relevant exposures, assessing related medical conditions, considering latency periods. It also means dealing with conflicts of interest among different groups, some of which may economically benefit from the environmental contaminants or hazards in question.

Symptoms arising from environmental hazards can sometimes be managed with specific medications as in the case of asthma.²² However, some environmentally related disorders and conditions are difficult to manage or may be untreatable, often because the exposure occurred during vulnerable stages of development (ie, prenatal, fetal or early childhood), setting the stage for serious chronic illness or neurological deficits later in life.²³

A traditional environmental approach seeks to identify exposures clearly linked with immediate health effects, for example, forest fire smoke triggering asthma attacks. However, if there is a latency period between an exposure and diagnosis (eg, early-life lead exposure leading to neurodevelopmental consequences), conclusions are often elusive. In addition, some well-documented associations between environmental hazards and children’s health are not commonly recognised within the health provider community, such as the link between ambient air pollution and adverse birth outcomes,²⁴ or the impact of pesticides on child neurodevelopment.⁸ During an assessment of a health outcome, more than one environmental risk factor is often identified. A process of prioritisation is then required, which is a challenging task considering the cumulative and interacting effects of many exposures.

The practice of CHE often involves seeking out others within the same home, school or community that may be affected by an identified exposure. Consideration of other health outcomes is also essential as many hazards are associated with a range of health effects. While causality is typically very difficult to assign in CHE, attempts to do so rely on long-established methods.²⁵ This involves relying on the basic concepts of the Bradford Hill criteria within a broader context of interacting environments, health and development, and human behaviour. Once identified and prioritised, mitigation of relevant risk factors is the definitive ‘treatment’ of environmentally related conditions, while symptoms and diagnoses are managed by conventional medical/surgical modalities. Designated resources for all the steps described are not readily available in Canada within the healthcare delivery budget.

Work carried out in the only CHE clinic in Canada, the Children’s Environmental Health Clinic (ChEHC) (www.ChEHC.ca), employs a collaborative approach and interdisciplinary team involving paediatricians, allied health professionals, public health specialists, educators as well as researchers. ChEHC cares for patients from across Canada and observes a variety of health concerns and exposures. Most frequently, parents report respiratory and neurodevelopmental issues in the children. Common exposures include indoor and outdoor air pollution (traffic, industry, wildfires, tobacco smoke, dust, mould, etc), lead and other heavy metals, chemical exposures and exposures in the home.

CHE in Canada began about 2 decades ago when the Pediatric Environmental Health Specialty Unit network was initiated.²⁶ While in Canada specific and dedicated funding is not available, the clinical component has been absorbed into the Alberta healthcare delivery budget. The University of Alberta has supported the education and research components.

Due to the broad scope of environmental health concerns complicated by the interdisciplinary nature of possible solutions, ChEHC underwent an engagement process seeking detailed input from numerous stakeholders into its agenda and organisation. One of the outcomes of this process was the development of an advisory board that supports various aspects of the programme.²⁷ Decisions made following an assessment of children regarding local environmental hazards may be multifaceted and complex. The advice provided by the multistakeholder advisory board has taught physicians where and how to advocate for specific policy changes in critical clinical situations. They have provided perspective, direction and support as ChEHC faces new and sometimes challenging issues. It has helped advance the CHE agenda forward and offers a valuable network of collaborators.

There has been a global movement towards recognition of CHE. In 2002, The Commission for Environmental Cooperation under the North American Free Trade Agreement launched a trinational initiative to identify CHE concerns.²⁸ A key concern was lack of CHE education and training in health providers globally.²⁹ The WHO responded by developing training modules on over 35 CHE topics.³⁰ These training modules are designed to help healthcare professionals learn the essentials of current CHE issues and transfer this knowledge to the community. The modules are continuously updated and expanded. The lack of health professional training in CHE recognised internationally led to the creation of a fellowship programme in the USA.³¹

In 2009, in Canada, the paucity of CHE training was noted with the majority of CHE education available only at the postgraduate level.³² Therefore, access is limited to those with special interest. More recently, Canadian family physician trainees report inadequate training in environmental health, which they considered an important topic.³³

Awareness of the impact of environmental exposures on child health worldwide is growing,³⁴ and parents include environmental disorders among the highest concerns for their children.³⁵ It is time to move this emerging subspeciality forward. Experts believe that to move the CHE agenda forward requires competence by physicians in the susceptibility of early life to environmental exposures and the effects on human health throughout the lifespan. Basic concepts to identify environmental links to health outcomes need to be solidly embraced by physicians and the community.

A fundamental approach to CHE includes an awareness of the potential causative exposures for many common as well as rare clinical conditions. Education on CHE therefore needs to occur much earlier in training of physicians, during periods that general health concepts are taught. This level of competency could be uniform globally and stimulate interest in later speciality training.

Training physicians to identify, assess and manage environmental risk factors requires interest and collaboration from higher education institutions around the world.

Understanding the impact of early-life environmental exposures on subsequent health outcomes in children and throughout the lifespan is likely to compel further action. This action may be directly through clinical work, research, education, health policy or advocacy.

Perhaps an important next step is for professional organisations at the local, national and international level to request global competencies for physicians in CHE. This will not only raise awareness of essentially fundamental concepts but also lead to their increased endorsement. Hopefully, this will lay the path for a collaborative effort to develop and publish the finalised core competencies in CHE.

It is critical to note the importance of health policy in protecting and improving the health of children globally. Children are highly vulnerable to the impacts of environmental exposures, especially those living in low- and middle-income countries and in low-socioeconomic status environments.^{36 37} Governments and policymakers around the world must make children a priority in decision-making processes. Policies that regulate industrial and consumer chemicals require companies to test the toxicity of chemicals that may be released, incorporating new assessment technologies and evaluate the effects of exposed populations should be considered.³⁸ Such actions would not only help prevent disease but also help ease the burden on the healthcare system and reduce costs.

CHE is a fundamental and emerging discipline that presents an opportunity to prevent common chronic symptoms and disorders by assisting families with identification and mitigation of relevant environmental risk factors. It is a field in need of increased attention and promotion. While the only children’s environmental clinic in Canada, also a designated WHO collaborating centre in CHE, includes in its mandate education of health professionals (www.ChEHC.ca), the work done by the centre is still a mere ‘drop in the bucket’. This may change if basic knowledge and practice on CHE became part of the required competencies for physicians.

Building physician competence in CHE concepts would facilitate a comprehensive approach when dealing with a clinical concern. In addition to treating diseases and mitigating the relevant specific environmental risks in affected communities, this would help to generate evidence and increase the awareness that is necessary to promote health and prevent diseases through healthy environments. In particular, physicians being trained into clinical paediatrics need to receive the necessary education and training to prepare for a significant shift towards incorporating CHE into a holistic preventive health paradigm within clinical paediatrics.