Metal pollution could trigger strokes and heart attacks in Brits – even in ‘low doses,’ according to new research.
The role of poisonous chemicals such as arsenic, lead, copper and cadmium in the development of cardiovascular disease has been ‘under-recognized’, say scientists.
In recent years exposure has become a major global health concern – with arsenic and cadmium known to cause cancer.
But evidence is growing heavy metals that find their way from materials like plastics and old pipes and fumes from industrial sites into the environment may also damage the heart and arteries leading to serious illness that can even prove deadly.
It could be as significant a factor as smoking, eating junk food and not getting enough exercise, according to a collaborative report published by Columbia University and Cambridge University scientists in the BMJ.
Heavy metals like arsenic, lead and cadmium get into our environment and bodies from sources like industrial plants and may be as significant a cardiovascular risk factor as smoking
Western countries such as the UK are not immune. These metals can turn up in the fish we eat – and other foods.
First study author Dr Rajiv Chowdhury, of Cambridge University, said: ‘It’s clear from our analysis there’s a possible link between exposure to heavy metals or metalloids and risk of conditions such as heart disease, even at low doses – and the greater the exposure, the greater the risk.’
Concern has often focused on the toxicity or carcinogenic properties of the metals – particularly at high doses.
But heavy metals may have other adverse effects on health – including heart disease and stroke, said the researchers.
And this could occur even at lower levels of exposure which might be prevalent in many parts of the world – including the UK and the US.
Arsenic, cadmium, lead and mercury are naturally-occurring compounds present at various levels in the soil, water and atmosphere.
They can also turn up in food and as we consume them, their accumulation in the body may lead to harmful effects over time.
Historically, these metals have found their way into our environment – and, ultimately, bodies – through the use of lead paint and pipes, which still exist in older buildings.
Despite marked reductions in these materials and their contaminants, heavy metal particles are still seething into our soil and air from plastics, batteries, tobacco smoke, and air water and dust near industrial plants and waste sites.
The finding is based on pooling data from 37 separate studies involving almost 350,000 participants – 32,512 of whom developed cardiovascular disease.
Results showed those exposed to arsenic, lead, cadmium and copper – but not mercury – were around 30 to 80 percent more at risk.
Dr Chowdhury says they ‘reinforce the often under-recognised importance of environmental toxic metals in enhancing global cardiovascular risk beyond the roles of conventional behavioural risk factors such as smoking, poor diet and inactivity.’
The study also highlights the potential need for additional worldwide efforts and strategies ‘to reduce human exposures even in settings where there is a relatively lower average level of exposure – such as many Western countries.’
Dr Chowdhury and his international team called for further detailed work ‘to better characterise these associations and to assess causality.’
They said the report is important because it highlights the need to tackle this environmental and public health problem.
It disproportionately affects people in low and middle income countries – but may still affect those in the UK and other developed nations.
Interventions need not be costly. Environmentally-friendly water filters or rinsing practices of rice and vegetables prior to cooking are currently being tested to reduce exposures at the household level.
They challenged the omission of toxic metal contaminants in water and foods from the recent World Health Organisation report on non-communicable diseases (NCDs).
Dr Chowdhury said: ‘While people shouldn’t be overly worried about any immediate health risk it should send a message to policymakers that we need to take action to reduce people’s exposure.’
Dr Maria Tellez-Plaza, a specialist in preventive medicine at the Carlos III Health Institute in Madrid and colleagues, reviewed the study for the journal and agreed metals are an important but neglected source of cardiovascular risk.
They described the review as ‘an important call for attention to an emerging group of risk factors with a high prevalence in populations around the world.’
Since metals are associated with cardiovascular disease even at relatively low levels of exposure ‘population wide strategies to minimize exposure will further contribute to overall cardiovascular prevention efforts,’ they said.
Editorial co-author Professor Ana Navas-Acien, of the Columbia Mailman School of Public Health in New York, said: ‘Despite widespread distribution of toxic metal contaminants, technical reports from environmental and public health agencies often disregard the mounting evidence of associated cardiovascular risk.
‘Similarly, metal exposures are neglected by the organizations that produce cardiovascular prevention guidelines.’