(NewsNation) — Deaths resulting from COVID-19 and other causes have led to a 4% decline in life expectancy for Americans from 2019 to 2021, according to the Centers for Disease Control and Prevention.

U.S. life expectancy at birth in 2021 was slightly more than 76 years, the lowest it’s been since 1996, according to a recent CDC report.

COVID-19 was the leading cause contributing to the change, followed by unintentional injuries, heart disease, chronic liver disease and cirrhosis and suicide.

NewsNation spoke with Scott Kush, a medical researcher at the Life Expectancy Group, about measures that could help stave off the virus and potentially reverse the declining national life expectancy.

The interview has been edited for length and clarity.

NewsNation: Is this something to be concerned about?

Kush: It absolutely is something to be concerned about … As a scientist, I go where the data goes, and the data on this continued to be bad for us as a population. I expected this drop (in life expectancy) for 2021. I expect that we’re not done with the drops and I think the drops will continue into the future.

NewsNation: What can we do to stay safer and live a little longer?

Kush: … Surgical masks have some value, but we’re talking about a highly infectious virus now … N95s are good, but they leak because they’re not fitted to a person’s face the way they ought to be … this means we need to move up a step and what that means is an elastomeric mask. The elastomeric mask is one that has a seal around the mouth and the face … you can have great protection almost up to an N99-level of protection with regular filter change. Really, the number one thing that we can do as a population to protect ourselves is wear a properly fitted mask. There’s nothing else that comes close to it. And then after that is stay up-to-date with any vaccinations that are available.

… People say ‘shouldn’t vaccination be number one?’ Vaccination is great, but with a vaccination, you’re assuming that the virus has already gotten into you … Why allow the enemy past the gate?

NewsNation: We live in a world now where some people have mentally moved past that. How do you protect yourself in a place where people aren’t wearing the same precautions?

Kush: Again: masks. The problem with masks is that they’re highly effective when everyone’s wearing them and the effective value of them drops precipitously if you’re the only one wearing them. But if you’re wearing an elastomeric or an N95 with a good fit, you should be able to withstand being in that public transportation space … but it means you have to be so much more cautious because other people are not wearing it.

NewsNation: What about the argument that you can’t let this prevent you from living your life?

Kush: In absence of clear public health policies that are protecting the population, this becomes an individual and a family decision. It’s tough. I don’t think people should be put in these situations, but they are, unfortunately, given the status of things. So there’s no answer here because the answer depends on you and your family and your balancing of risks and rewards and life.

NewsNation: What else should we consider about the virus and life expectancy?

Kush: We’re at a critical juncture. Rather than throwing caution to the wind, we really ought to learn from history and ought to take some cautious moves as a population about how we approach our movements into the future.

NewsNation: Does the impact of COVID-19 on the country’s overall life expectancy tell us anything about how the pandemic was handled?

Kush cont.: First, we have to take a look at what has actually happened from the number standpoint. We have appreciated decades after decades of growth in life expectancy in this country — close to 70% improvement of life expectancy since the year 1900, when it was 47. We were approaching approximately 79. That’s like an extra life … so we have achieved phenomenal gains through public health … but we have to put things into context.

A four-year drop across a two-year timeframe is a lot. It’s a lot for modern day United States. It’s a lot for modern day any country. However, you always have to go back historically and look at things how they once were. In the last pandemic, which basically lasted from 1918 to 1922, there was a drop in the first year of 12 years of life expectancy for men. That was a 25% drop … Now we have a three-year drop out of 79. That’s a 4% drop. So as orders of magnitude are concerned, this is a much lower drop than what we saw back then…

However, there is something here that might be different from that pandemic, and that is the long-term impacts of the (COVID-19) infection … Data that have been emerging in the past year or so have led to the possibility that what’s actually happening is you don’t just have the acute risk of infection, you have a very long-term risk of comorbidity and future death.