In the charcoal fields of San Pedro, a bustling port city in the southwest Ivory Coast, hundreds of women and children — some barely school-age — toil day and night among heaps moldering wood, waste water and air thick with smoke. Driving rain, withering heat and sawdust storms come with the job. This used to be men’s work. Not anymore.

Making charcoal for sale out of the refuse from nearby sawmills, work for the desperate and destitute, has become almost exclusively women’s work in San Pedro. It may have started with one widow from Bogart, a desperately poor slum, who ventured into one of the three charcoal fields in San Pedro, the Parc Du Pont, intent on making a dollar to feed her family.

As Joana Choumali learned when she began documenting the women in 2013, men are happy to sell wood, San Pedro’s largest export, and let women keep the filthy, back-breaking work of making charcoal. Ms. Choumali, a freelance documentary and fine art photographer from Abidjan, was on an assignment in San Pedro when she first spotted the phenomenon.

Three years later, Ms. Choumali’s project, “Sissi Barra (The Work of Smoke),” illustrates the harsh reality for women with few choices, the poorest of the poor, in the Ivory Coast. While the country is enjoying an economic revival and now boasts Africa’s fastest growing economy, the charcoal producers of San Pedro live like paupers. Her conversation with Evelyn Nieves has been condensed and edited.