The Zika virus outbreak makes it clearer than ever: It’s time to end the ban on DDT — a ban that was never sensible in the first place, but now is downright unjustifiable.

The Centers for Disease Control and Prevention reports that Zika has infected nearly 300 pregnant women in the United States, putting their babies at risk for a devastating birth defect. This summer, as many as 40 million Americans will visit regions where carrier mosquitoes thrive, including large swathes of the South.

There’s also a moderate risk of Zika-carrying bugs in New York City, and parts of the city offer Zika mosquitoes the perfect conditions in which to thrive.

That means hundreds of babies are at risk of a horrifying brain defect called microcephaly. Infants who don’t perish outright need extensive care, which can cost up to $10 million.

Unfortunately, alarmism has led to a decades-long ban on the most effective pesticide against the disease-spreading mosquito, even though science has proven it reasonably safe.

Mosquitoes are responsible for more deaths than any other creature on earth. DDT kills mosquitoes most effectively; in the 1960s, the National Academy of Sciences said that “to only a few chemicals does man owe as great a debt as to DDT,” adding that it had prevented as many as 500 million deaths.

Nonetheless, the United States continues to enforce its 1972 ban on DDT, citing dubious health and environmental concerns.

Numerous studies directly contradicted environmentalists’ claims that the chemical caused cancer. Likewise, thousands of studies examining other purported health risks produced results that were “weak, inconclusive or contradictory; in other words there is no evidence of harm,” Namibian health minister Richard Nchabi Kamwi noted in The Wall Street Journal.

Claims of damage to the environment proved equally nebulous. Rachel Carson, the environmentalist who drove the DDT ban, based her argument on several fraudulent claims.

For example, she claimed DDT had rendered the robin “on the verge of extinction” — and that same year, America’s foremost ornithologist declared it “the most abundant bird in North America,” the Journal of American Physicians and Surgeons noted more than a decade ago.

Yet Carson’s junk science won out, and not just in the United States.

The Zika-carrier Aedes aegypti mosquito is already a hearty bug, capable of breeding in small puddles of water and thriving in tough urban environments. It has also, tragically, proven especially resilient to alternative pesticides.

Latin America had nearly eliminated the Aedes aegypti mosquito using DDT in the last century. But the scaremongering that began in the United States spread south, and with it, the mosquito population surged, bringing Zika with it.

Globally, discouraged use of DDT has come at enormous human cost; Dr. Rutledge Taylor’s documentary estimated that the DDT ban could be linked to as many as 1.5 million unnecessary deaths a year.

It’s bad enough to ban the most effective Zika-fighting tool we have. Even worse, the same sort of unscientific dogma is behind an effort to regulate other safe, effective pesticides at precisely the time they’re most needed.

In April, at the behest of concerned environmentalists, Orange County decided against aerial spraying for mosquitoes — even though 17 of its residents have died from West Nile infections over the last two years, with hundreds more infected.

Likewise, more than 55,000 acres of private land in Massachusetts will go unsprayed this summer out of environmental and health concerns, despite the increased risk of West Nile.

Meanwhile, the alarmism continues to spread like wildfire. Argentine environmentalists recently claimed that the pesticide pyriproxyfen — not Zika — is the real cause of the microcephaly boom. Scientists across the globe are now struggling, with varying success, to debunk this rumor to a credulous public.

“It’s ridiculous,” one top microcephaly expert recently told USA Today. “These guys come out of the blue, and people believe them, with no evidence at all.”

Thanks to environmentalists, Zika-caused deaths and diseases are preventable tragedies. So let’s start preventing them.

Jillian Kay Melchior, political editor at Heat Street, is a fellow with the Independent Women’s Forum.