For months, worried parents in Flint, Michigan, arrived at their pediatricians' offices in droves. Holding a toddler by the hand or an infant in their arms, they all had the same question: Are their children being poisoned?
To find out, all it takes is a prick of the finger, a small letting of blood. But if the tests come back positive, the potentially severe consequences are far more difficult to discern.
That's how lead works. It leaves its mark quietly but years later, when a child shows signs of a learning disability or behavioural issues, lead's prior presence in the bloodstream suddenly becomes inescapable.
The Hurley Medical Centre released a study in September that confirmed what many Flint parents had feared for over a year: the proportion of infants and children with above average levels of lead in their blood has nearly doubled since the city switched from the Detroit water system to using the Flint River as its water source in 2014.
The crisis reached a nadir on Tuesday, when Flint Mayor Karen Weaver declared a state of emergency. "The City of Flint has experienced a man-made disaster," Weaver wrote in a declaratory statement.
The mayor, elected after her predecessor Dayne Walling experienced fallout from his Administration's handling of the water problems, said that she was seeking support from the federal Government to deal with the "irreversible" effects of lead exposure on the city's children.
Weaver believes that these health consequences will lead to a greater need for special education and mental health services, as well as developments in the juvenile justice system.
But Weaver doesn't think the city can receive the help it needs without alerting federal officials to the urgency of the matter.
To those living in Flint, the announcement may feel like it's been a long time coming.
Almost immediately after the city started getting its water from the Flint River in April 2014, residents began complaining about the water, which they said was cloudy in appearance and emitted a foul smell.
Since then, complications from the water coming from the Flint River have only piled up. While city and state officials initially denied that the water was unsafe, this January saw the release of a state notice informing Flint residents that their water contained unlawful levels of Trihalomethanes - a chlorine byproduct linked to cancer and other diseases - and as a result was in non-compliance with the federal Safe Drinking Water Act.
The use of the Flint River was always supposed to be temporary, meant to end in 2016 after a pipeline to Lake Huron's Karegnondi Water Authority.
On October 16, water started flowing again from Detroit to Flint.
This, too, held a sense that it had come too late, particularly for the parents of children who may have been permanently affected.
These parents and other Flint residents filed a class action federal lawsuit against the state, the city and public officials this November for damages suffered from the tainted water.
Poison in the water
According to the World Health Organisation, "lead affects children's brain development resulting in reduced intelligence quotient (IQ), behavioural changes such as shortening of attention span and increased antisocial behaviour, and reduced educational attainment.
Lead exposure also causes anaemia, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs. The neurological and behavioural effects of lead are believed to be irreversible."