World Toilet Day has once again passed with all the pomp and ceremony that its name suggests. But in the face of serious health and development consequences, it is time for world leaders to do some bathroom reading.

This past month saw Malcolm Turnbull join other world leaders for the ASEAN, APEC and East Asia Summit (EAS) annual gatherings. Commentary around the summits focused largely on the clash between openness on the one hand and Donald Trump’s brand of ‘America First’ protectionism on the other. Absent, unsurprisingly, from any of the leaders’ discussions was a subject arguably critical to economic development yet long neglected. Toilets! Or rather the lack of them.

Sunday 19 November marked World Toilet Day, an official UN day established in 2013 to draw attention to the fact that 4.5 billion people, or over half of the world’s population, lacks access to safe sanitation.

World Toilet Day seeks to raise awareness of the entirety of the sanitation challenge. For instance, 892 million people still practice open defecation, more than 5 million of them reside in the host of last week’s EAS, the Philippines. Additionally, countries like Indonesia and Bangladesh face major waste treatment challenges, particularly in cities and slums, many of which do not have sewerage and require onsite sanitation solutions, such as faecal sludge management, to ensure waste is safely treated rather than dumped into local land or water sources.

So why should Prime Minister Turnbull, and some of the region’s top economic and political forums, weigh in on what has been labelled a global sanitation crisis? The answer lies in the huge economic costs it carries. A few years ago, the World Bank estimated that inadequate water supply and sanitation drains US$260 billion (AUD$350 billion) each year from the global economy due to lost time and productivity. And it has been estimated that in India alone, more than 5 per cent of the country’s GDP is lost each year due to poor sanitation.

Addressing the sanitation crisis would boost livelihoods, public health and ultimately trade and investment. Currently, in large part as a result of poor sanitation, diarrhoeal-related diseases are the second biggest killer of children under the age of five. Being able to grow up to be productive citizens, these children have the potential to be future consumers of Australian goods and services. Indeed, according to the World Health Organization (WHO), for every US dollar invested in sanitation there is estimated to be an economic return of four US dollars. Meanwhile, achieving universal sanitation for all would carry a minimum economic benefit of over USD$220 billion annually.

Yet, for all the talk of inclusive growth, few leaders strutting the world stage—with the notable exception of Indian Prime Minister Narendra Modi— have given the issue of sanitation, and its importance to economic development and health, the proper attention it deserves.

The absence of sanitation from any key ASEAN, EAS, G20 or APEC initiative contrasts heavily with an emerging and dynamic movement of activists calling for change: inspiring individuals who are willing to tackle this massive and urgent challenge. At Global Citizen, there have been opportunities to meet many of them, including a courageous young woman from Bangladesh named Shomy Chowdhury.

Ever since Shomy’s mother passed away in 2014 from lack of safe sanitation and hygiene, Shomy has committed herself to educating communities in Bangladesh, as well as around the world, about practicing safe sanitation and hygiene. Through our work alone almost 200,000 citizens, global citizens, have rallied behind Shomy’s campaign which was recently given a helpful push by a profile piece in Bangladesh’s biggest national newspaper, Prothom Alo.

Leaders are starting to listen. In September, Shomy met with various heads of government, foreign ministers and ambassadors on the margins of the UN General Assembly in New York. Now governments, institutions and businesses need to respond. After all, there is no shortage of opportunities to make a difference on this critical issue.

Singapore for instance is uniquely placed to drive this issue to the top of the global agenda. In 2013, Singapore sponsored its first ever motion in the UN General Assembly. What was the cause? To establish World Toilet Day—initiated informally years prior by a Singaporean citizen, Jack Sim—as an official UN day. To date though, this leadership on sanitation has remained largely confined to the personal initiative of its ambassadors at UN headquarters in New York rather than a top priority of the government as a whole. Taking over the chair of ASEAN and EAS next year, Singapore has the opportunity to make this a core foreign policy priority, challenging all countries to bring something to the table and make substantial and concrete pledges towards sanitation domestically and abroad.

This could have some profound and not inconsequential results. Imagine Canada’s Prime Minister Justin Trudeau, who made his ASEAN and EAS debuts last week in the Philippines, being told the price for entry into next year’s summit is to match his strong support for gender equality with an equal commitment to sanitation for all? Not only would he make a powerful advocate but it would also be consistent with his country’s feminist foreign policy, given women face sexual and physical violence when defecating out in the open.

Australia too is well placed to lead on this issue. Malcolm Turnbull is one of 11 heads of government currently serving on the High Level Panel on Water. Co-convened by the UN and World Bank last year, the panel is expected early next year to lay out a roadmap to achieving universal access to water and sanitation by 2030. The Australian government should ensure that firstly this blueprint for action includes concrete solutions for addressing the scale of sanitation crisis. This includes investing in faecal sludge management and behavioural change programs aimed at promoting the usage of toilets. Secondly, it should encourage other countries to adopt these recommendations by setting a strong example itself. Global Citizen has suggested to the government that it set an ambitious target to use its resources to provide sanitation to at least 50 million people by 2030. After all, in an age when talk is cheap, action is what ultimately matters.

The 4.5 billion people living without sanitation, the national and global economies, and activists like Shomy Chowdhury are counting on leaders throughout the Asia-Pacific. They are counting on these leaders, including Malcolm Turnbull, to step up for sanitation and end this global crisis once and for all. This past World Toilet Day serves then, not only as a stark reminder of the gravity of the sanitation challenge, but also as a challenge to our leaders to work together towards achieving a safer, healthier, more prosperous and peaceful world through improved global sanitation.

Michael Sheldrick is vice president of global policy at International Advocacy Group, Global Citizen.

Talia Fried is manager of global policy at Global Citizen.

This article is published under a Creative Commons Licence and may be republished with attribution.