Why WHO is applauding India’s big move to go mercury-free in health care

Recently, WHO hailed India’s efforts to phase out mercury from medical devices, calling it a critical step toward safer healthcare systems and healthier communities. Mercury, long used in medical devices, is highly toxic and is classified by the World Health Organisation as one of the top ten chemicals of major public health concern for its harmful effects on the brain, nervous system, kidneys, lungs and developing foetuses. Its pollution does not remain local but spreads through air, water and soil, exposing people and ecosystems far from the source. 

Against this backdrop, India’s shift toward mercury-free healthcare has emerged as a significant public health and environmental achievement. Here is a look at why it matters. 

Mercury in medical devices

Over the centuries, mercury-containing medical measuring devices (MCMMDs) became deeply woven into medical practice. The first mercury-added thermometer was developed by Daniel Fahrenheit in early 18th-century Germany, while mercury sphygmomanometers became standard by the late 19th century. Their dominance persisted largely because mercury’s physical properties, uniform expansion and visible movement made it ideal for precise measurement. However, by the early 2000s, high-income countries began phasing out these devices, driven by growing evidence of mercury’s health and environmental consequences. 

A major turning point came with the Minamata Convention on Mercury, a global treaty designed to protect human health and the environment from mercury exposure. The Convention restricts the manufacture, import, and export of several mercury-added products, including non-electronic thermometers and sphygmomanometers, except in limited cases where no viable alternatives exist. In healthcare settings, mercury releases are most often linked to broken equipment and improper waste management, small spills that can lead to significant indoor air contamination, as mercury evaporates at room temperature. 

How India is phasing out mercury from healthcare

As the WHO states, “For decades, a thin silver thread of mercury lay at the heart of medical care in India, inside thermometers tucked under tongues, sphygmomanometers strapped around arms, and equipment stored in clinics across the country. But that familiar glint masked a dangerous truth.” 

As a party to the Minamata Convention, India has committed itself to reducing and eventually eliminating avoidable mercury use. The country’s journey toward mercury-free medical devices began earlier than many realise. In 2007, Delhi became the first state to announce a complete phase-out of mercury-based devices from its public health facilities, setting an early precedent. 

This momentum was strengthened in 2010, when the Directorate General of Health Services under the Ministry of Health and Family Welfare issued a directive integrating mercury-free devices into the Indian Public Health Standards (IPHS). The requirement was further reinforced through national accreditation and quality frameworks such as National Quality Assurance Standards (NQAS), Kayakalp, and the National Accreditation Board for Hospitals and Healthcare Providers (NABH). Together, these measures ensured that mercury-free healthcare was not just encouraged, but institutionalised.

Environmental governance followed suit. In 2012, the Ministry of Environment, Forest and Climate Change framed the Guidelines for Environmentally Sound Management of Mercury Waste from Healthcare Facilities, addressing the longstanding issue of unsafe disposal practices. These guidelines aimed to prevent mercury from entering waste streams, water bodies, and soil, an often overlooked but critical pathway of exposure. 

With policy support firmly in place, the transition moved from regulation to practice. Non-toxic alternatives such as digital thermometers, aneroid blood pressure monitors, and advanced electronic devices became increasingly common across public hospitals. While early resistance persisted, particularly over concerns about cost and accuracy, improvements in digital technology and routine calibration gradually settled these debates.

Allaying such concerns, Dr Anupam Prakash, Head of the Department of Medicine at Lady Hardinge Medical College, Delhi, notes that digital blood pressure devices are “regularly calibrated to ensure accurate and reliable readings.” Clinical confidence has also grown around patient safety. 

“We faced problems with mercury thermometers — there was the risk of children and seizure patients biting the thermometer, leading to the accidental ingestion of mercury,” says Dr Preeti Gupta, Associate Professor, Department of Cardiology at Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi. “With the digital thermometers, there is no such hazard, and we have been using it in our department.” 

WHO has played a key supporting role in this transition. In nationwide assessments conducted to track progress and identify gaps, WHO found that most public health facilities in India have already phased out mercury-based medical devices. 

“WHO India will continue to support the Government to ensure that the remaining public health facilities complete this transition, and that India establishes robust systems for sound management of mercury waste,” says Ms Payden, Acting WHO Representative to India. 

Why we need mercury-free medical devices

The case for mercury-free medical devices rests firmly on science. Elemental mercury, traditionally used in thermometers and sphygmomanometers, can vaporise when a device breaks. Inhaling mercury vapours damages the lungs, kidneys, and nervous system, and even small exposures can have lasting effects. WHO emphasises that these risks are entirely preventable, given the availability of safer alternatives. 

According to WHO, “When released in the environment, elemental mercury can be converted to the more bioavailable methylmercury by microorganisms present in water and soil. Methylmercury accumulates in the muscle tissue and this bioaccumulation in organisms leads to biomagnification in the food chain. Unborn children and nursing infants are the worst affected.” 

Research from India highlights that mercury devices are still present in some hospitals and are often disposed of incorrectly. A study across 113 government and corporate tertiary-care hospitals found that mercury-containing items continue to be used. The most common disposal method involved collecting broken devices in plastic bags labelled as hazardous waste, an approach that reduces immediate exposure but does not eliminate environmental risk. While hospital effluents in the study showed mercury levels below permissible limits, researchers warned that continued use and disposal contribute to cumulative environmental contamination. 

“Environmental pollution due to mercury has raised serious concern over the last few decades,” the study notes. “Various anthropogenic sources including the health sector play a vital role in increasing the mercury load on the environment.” 

Clinical studies show that mercury-free sphygmomanometers can deliver blood pressure readings comparable to traditional mercury devices. Researchers developed Merkfree using Galinstan, a non-toxic alloy, to replicate the look and functioning of mercury sphygmomanometers. Based on trials in 252 patients, the device showed “good correlation” with mercury and oscillometric devices, with errors below 10 percent, making it a viable alternative that supports the WHO’s goal of eliminating mercury from healthcare. 

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.