Imagine that within the same hour, two large Boeing 747 passenger jets crashed killing everyone onboard. Now consider two planes crashing every hour for an entire 24-hour period. Finally, think of the accumulated deaths of two passenger jets crashing every hour for an entire year.*

The death toll from all those crashes would be roughly equivalent to the number of people who die every year from pollution.

A new study published in the British medical journal The Lancet finds that 1 in 6 deaths around the globe are due to polluted air, soil, water, and work environments. That’s 9 million premature deaths in 2015 caused by pollution.

Here are some of the findings from the study, as reported by STAT:

Pollution disproportionately impacts the poor. More than 90 percent of all deaths tied to pollution occur in e and e countries. And across all countries, diseases driven by pollution are most prevalent among minority populations.

Deaths from some types of pollution have been on the decline. Deaths tied to household air pollution, water pollution, and poor sanitation are declining, in part thanks to vaccines that treat diseases spread through dirty water.

Deaths tied to other types of pollution are rising. An estimated 4.2 million deaths in 2015 were attributed to air pollution, a big jump from 3.5 million in 1990.

Lead pollution contributed to half a million deaths in 2015. Health problems including high blood pressure, renal failure, and cardiovascular disease are associated with lead exposure in adults.

The health impacts of pollution take a financial toll. Pollution-related diseases account for up to 7 percent of health spending in developing countries dealing with heavy pollution. In wealthy nations, they account for nearly 2 percent of annual health spending.

Addressing pollution can save money. The researchers report that every dollar invested in U.S. air pollution control since 1970 — when the Clean Air Act passed — has produced roughly $30 in benefits. Much of es from increased productivity from healthier people.

Because the United States has e significantly cleaner since the 1970s, we Americans often underestimate the problem of global pollution. We also forgot how we became a less polluted nation.

As the Lancet study notes, there is benefit to be gained by pollution regulations that protect us from the tragedy of mons-type problems. But for most of the world, the problem is not a matter of regulation but of poverty and underdevelopment. For example, one of the world’s largest single environmental health risk is air pollution, and many of the deaths are due to household air pollution (HAP) caused by the inefficient use of solid fuels.

Every day almost half the planet’s population is exposed to toxic amounts of HAP because they use solid fuels, a term that includes biomass fuels (derived from plant sources) or coal bustion resulting in the release of products of bustion such as carbon monoxide and particulate matter. The problem arises because solid fuel monly used in homes with poor or absent chimney ventilation of smoke. What the world’s three billion energy-poor people need is what those of us in the West take for granted: cheap electricity to cook their food and heat their homes.

The only effective long-term solution to HAP is to reduce energy poverty. And the only effective long-term solution to energy poverty is economic growth. Long-term economic growth, however, is dependent on increasing economic freedom, the rule of law, and access to markets in developing areas.

Such preconditions are much more difficult to implement than actions that merely require passing laws that ban environmentally harmful actions. But that’s what the poor need most—and what Christians should be leading the way in bringing to the world.

*This illustration is borrowed from this Quartz article and modified to fit the data released by The Lancet study. The figure is based on the typical two-class layout of a Boeing 747, which can hold 524 passengers. Two jets crashing per hour would kill 1,018 people. Since there are 8,760 hours in a year, the total annual deaths from two plane crashes per hour would be 8,917,680.