NEW YORK (BLOOMBERG) - Anyone reading about the Trump administration's refusal to block agricultural use of a dangerous pesticide may find themselves staring at a bag of oranges, thinking: Will these hurt my family?

Probably not. While consumers trundling through US supermarkets might fear for their children's health, those most at risk are a small subset of kids in the US.

Mostly Hispanic, they are children whose parents are often undocumented immigrants who live near the farms from which that pesticide-laden produce came, work in those fields, or both.

On Wednesday, Scott Pruitt, the new head of the US Environmental Protection Agency, signed an order effectively rejecting his agency's advice to ban chlorpyrifos, a popular insecticide, from being used to keep bugs off such crops as walnuts, broccoli, and oranges.

Chlorpyrifos is a member of the pesticide class organophosphates. Multiple studies show that eating food grown with the pesticide will in turn expose you to it, with children especially susceptible to its risks.

But it's far worse for those who live and work around the chemical, and worse still if they do both.

A November 2016 report from the EPA's Office of Chemical Safety and Pollution Prevention found that just by eating such produce, children one to two years of age get a dose that's 140 times the agency's safety threshold.

While a 2010 study found an association between organophosphate exposure and attention deficit/hyperactivity disorder, it didn't establish a causal link. The data were also weighted to represent the entire US population of children aged 8 to 15.

A nexus, however, becomes clearer when examining populations closest to where the pesticides are used.

Multiple studies show a connection between prenatal exposure in pregnant women and poorer cognitive function in their offspring.

Among these was a 2011 study of 329 children of predominantly Mexican-American farmworkers in California's Salinas Valley, frequently referred to as the world's "salad bowl."

Researchers found that 7-year-old children born to mothers with the highest levels of prenatal organophosphate exposure had IQs an average of seven points lower than mothers who had lower exposure levels.

A 2014 University of California-Davis study found that children of mothers who, during their second trimester, lived within 1.5km of chlorpyrifos-treated fields were more than three times more likely to develop autism. Other studies evaluating impacts of organophosphates used as pesticides in the home have reached similar conclusions; notably, the EPA banned chlorpyrifos for most household uses in 2000.

A 2014 report from the California Department of Public Health underscored the racial disparity at play in the pesticide's deployment.

In examining the 15 counties with the most agricultural use, it found that Hispanic children were 46 per cent likelier than their white counterparts to attend schools within 400m of pesticide use.

As pesticide intensity increased, so did the disparity: Hispanic children were 91 per cent more likely to attend a school near the highest level of pesticide use than were white children.

Even without stepping foot on a field, members of farmworkers' families are exposed through drift and what sticks to bodies and clothes, said Miriam Rotkin-Ellman, a senior scientist at the Natural Resources Defense Council. The children are often exposed through diet as well-what she called a "double whammy."

The EPA and CropLife America, the national trade association representing pesticide makers, didn't respond to requests for comment on any disparate impact of chlorpyrifos use.

In a statement March 30, CropLife called a study describing the chemical's risks "unreliable" while hailing the administration decision as "a hopeful indication that the EPA is recommitting to adherence to established requirements and guidelines relating to transparency, public process, and scientific integrity."

Angel Garcia, a organiser with El Quinto Sol de America, a farmworker advocacy group in California's Tulare County, warns that the EPA decision will "negatively impact these communities."

Sarah Aird, co-director of the Californians for Pesticide Reform coalition, ascribed political motivation to the Trump administration's decision, noting the disproportionate impact the pesticide has on rural communities that attract undocumented immigrants in search of work.

"It's up to California to step up to protect the most disenfranchised among us," Aird said.