About 2.3 billion people around the world lack access to basic toilets. This leads to poor sanitation and about 280,000 people per year die as a result. But the global sanitation crisis isn't equally distributed.
Women in developing countries are disproportionately burdened by the persistent lack of access to sanitation in their homes, communities, schools and public spaces.
Women and girls who rely on shared toilets, at schools or in densely populated urban settlements, lack privacy, safety and hygiene to comfortably manage their daily toilet and menstruation needs.
This threatens their health. Exposure to harmful bacteria in unsanitary environments puts women at risk of urinary tract infections, toxic shock syndrome and vaginal infections.
Holding in their urine and faeces also puts them at risk of dehydration and haemorrhoids.
We carried out a study in Mathare Valley informal settlement in Nairobi, Kenya to better understand women's daily sanitation practices and what influences their decision to use facilities in the settlement.
Seven years ago there were about 144 public toilet facilities in Mathare. Anywhere from 17 to 232 people relied on a single toilet and over 70 percent of residents had to walk more that 50 meters to reach a toilet.
Since then, there've been concerted efforts by non-governmental organisations and the government to increase the number of toilets in Mathare.
For instance Sanergy, a social venture, has launched more than 140 toilets in Mathare. But many of the existing toilets still require payment to use, between KES 3 and KES 10 per month (US$0.03 - US$0.10).
Despite the growing availability, many women still don't always use them.
In our study we found that about one-third of women relied on a bucket, plastic bags or open defecation at least once during the day and over two-thirds rely on those methods at night.
This means that its not just access that's the issue. Many women aren't using the new facilities because of concerns over their safety, privacy, health and ability to pay to use them.
Future interventions must address these problems – and not just supply toilets – if sustainable gains in this important public health area are to be achieved.
Informal settlements
About 6.5 million of Kenya's 45.5 million people live in urban informal settlements. The population living in these settlements increased by more than three times, from 1.5 million to more than 6.4 million between 1990 and 2014 and is still expected to keep growing.
This will exacerbate the challenges women face when it comes to sanitation.
We collected data in two phases between 2015 and 2017. During the first phase we partnered with representatives from the University of Nairobi and female residents from Mathare to conduct in-depth case studies with 55 women living in Mathare.
In the second phase we worked with female residents in Mathare to carry out 550 household-level surveys with women.
We found that, about 40 percent of women relied on public toilets for some of their sanitation needs during the day, but are unable to rely solely on these toilets.
Within 24 hours, 75 percent of women relied on plastic bags or buckets at least once for their ablutions. They then dispose of these in open drains or rivers near their homes.
This is surprising. Over the last few years there have been efforts to increase access to toilets in Mathare.
Notable among them are Sanergy's fresh life toilets, Grand Challenge Canada's funded Banza toilets and a government effort under the National Youth Service's slum improvement project. Each of these projects focused on some aspect of increasing access to sanitation, from provision of innovative toilets to household rubbish collection, drainage cleanup, and toilet construction and management.
A number of factors prevent women from regularly using the facilities.
Women fear victimisation – like sexual assault, rape, or theft – poor cleanliness and a lack of privacy. On average, toilets in Mathare are shared by 70 people, with many being used by hundreds of people.
This makes it very difficult to maintain them.
We found that one or more of the stalls at public toilets have missing doors or locks, are flooded or blocked, or aren't cleaned well. Several of the public toilets, which have separate sections for men and women, aren't always open or have closed one of the gender sections.
Having to share facilities is a factor that makes women feel insecure, particularly at night.
The women didn't see the toilets as safe spaces. They also don't feel safe in the settlement. Participants said they felt unsafe leaving their homes at night, even if the toilets were located within a short walking distance.
Another reason women wouldn't use the facilities is because most charge them, and they can't afford to pay. Most toilets in Mathare charge a pay-per-use fee between KES 3 and KES 10 per month (US$0.03 - US$0.10). A family fee is between KES 100 and KES 150 (US$1 - US$1.50).
The average household income in Mathare is about KES 8500 (US$85), and estimated monthly expenditures often exceed this amount. This leaves little or no money for spending on sanitation.
On top of this, we found that some women don't have the decision making power or control over household spending to allocate additional funds to sanitation.
Interestingly, many of the community toilets in Mathare have separate urinals for men that are free to use but there's no setup like this for women.
Solutions
When we asked the participants what would work for them, some suggested they needed more access to free urinals – one or two stalls in a public toilet facility – that they could use for urination and to change menstrual pads.
We also suggest that policymakers need to start accounting for other challenges to sanitation access, like strategies that increase women's safety and privacy, especially at night. For example, better lighting in and around public toilets or community or technological innovations to help women feel safer when accessing public toilets. 
Samantha Winter, Postdoctoral fellow, Rutgers University.
This article is republished from The Conversation under a Creative Commons license. Read the original article.