The world’s immigrant population doesn’t pose any notable risk to public health and, in fact, contributes to many of the health services in countries they migrate to, despite dire claims by right-leaning politicians and a rise in xenophobia, according to a study released Wednesday.

The report, the result of a two-year commission by University College London and the Lancet, a medical journal, targets an uptick in anti-immigration policies around the world in recent years, notably under the administration of President Donald Trump and surrounding Britain’s decision to leave the European Union.

A cohort of 20 experts analyzed nearly 100 studies and found about 1 billion people were moving or had moved in 2018, about a quarter of which crossed international boundaries. The number of refugees and people fleeing violence or natural disasters has skyrocketed this year, and the topic has become a political hot point through Europe and the United States.

But these immigrant populations are beneficial to rich nations, the authors found, often traveling for an education or working in roles that contribute to local economies. In Britain, for example, 37 percent of doctors work with medical qualifications they received in another country.

“In too many countries, the issue of migration is used to divide societies and advance a populist agenda,” Richard Horton, the editor of the Lancet, said in a statement. “Migrants commonly contribute more to the economy than they cost, and how we shape their health and wellbeing today will impact our societies for generations to come. There is no more pressing issue in global health.”

Around the world, right-leaning politicians have moved to demonize a growing migrant population, and myths about such people have spread like wildfire. Conservative commentators on Fox News have made false claims that refugees carry “diseases” that would infect people in the United States. Trump has regularly attacked members of a migrant caravan as criminals, without evidence.

“Populist discourse demonizes the very same individuals who uphold economies and bolster social care and health services,” Ibrahim Abubakar, the chair of the commission and a professor at University College London, said in a statement. “Questioning the deservingness of migrants for health care on the basis of inaccurate beliefs supports practices of exclusion, harming the health of individuals, our society, and our economies.”

The study also found that migrants in rich countries have lower rates of mortality than the nations’ general populations and were less susceptible to a slew of health issues, including cardiovascular disease, mental and behavioral issues and blood disorders. Fertility rates among migrant populations are also lower.

Migrants do have increased rates of HIV, tuberculosis and viral hepatitis, but the report found the transmission of such ills to the general population was “negligible.”

“Contrary to the current political narrative portraying migrants as disease carriers who are a blight on society, migrants are an essential part of economic stability in the U.S.,” Terry McGovern, a professor at Columbia University and a co-author of the study, said in a statement. “The separation of migrant children from their parents creates long-term psychological damage — and is a cruel and unnecessary aspect of U.S. policy. …Migrants are vital to our wellbeing as a society.”