An Independence Day fireworks display at Mount Rushmore National Memorial could expose spectators to Covid-19 as well as toxic fumes from the explosions/Kurt Repanshek file

While Big Bend National Park closed Thursday due to a confirmed case of Covid-19 within the park, other parks are moving carefully in granting visitors access, and at least one concessionaire is requiring customers to wear facemasks, an Independence Day celebration at Mount Rushmore National Memorial will not require face masks or social distancing.

The event prompted by the Trump administration and which will feature President Trump in attendance also comes two days after a study stated that spectators could be exposed to toxic emissions from the metals used to give fireworks their brilliant colors.

Upwards of 7,500 spectators are expected for the spectacle, which will be held Friday night, July 3. South Dakota Gov. Kristi Noem has said face masks will be available for those who want them, but social distancing won't be enforced.

On Wednesday, Xanterra Travel Collection, which operates lodges and other concessions in and around Yellowstone, Glacier, Grand Canyon, Death Valley, Rocky Mountain, and Zion national parks, as well as at Mount Rushmore, announced that it would require "all visitors to wear face coverings while in the indoor public areas of our facilities and in outdoor areas where proper distancing is not possible. These areas include, but are not limited to lobbies, hallways, gift shops, restaurants, offices, indoor/outdoor queueing lines, and sightseeing vehicles and boats."

The National Park Service has not taken a hard stance on the wearing of face masks, though many parks have encouraged visitors to wear them if they can't practice social distancing. At Golden Gate National Recreation Area, officials said "federal, state and local health authorities are were discourging any activities that would draw large crowds" beause of the coronavirus pandemic.

The fireworks display over the carved faces of Presidents George Washington, Theodore Roosevelt, Abraham Lincoln and Thomas Jefferson comes 11 years after they were halted because of concerns they might spark wildfires in the surrounding Black Hills National Forest and the Norbeck Wildlife Preserve.

Fire danger in those areas surrounding Mount Rushmore currently is judged to be "moderate."

The environmental assessment prepared on the question of whether the fireworks display could safely return to the memorial noted a number of adverse effects it would create, but dismissed them as short-term.

Air Quality Issues

Air quality may be affected by emissions from the vehicles of visitors, fireworks contractors, and NPS and event partners before, during, and after the event. These impacts would be no greater than, and possibly less than, normal memorial operations because of the limited number of visitors on that day compared to other summer days. There may be air quality impacts from the potential use of helicopters for event staging and teardown, and by military aircraft from a potential flyover. These impacts would be a negligible addition to regular aircraft traffic in the region. Air quality could also be affected by smoke from the fireworks display; however, these effects are expected to be short-term and negligible and smoke would be expected to dissipate soon after the event. 

Impacts to threatened or endangered species

The northern long-eared bat (Myotis septentrionalis) is listed as threatened under the ESA and is present at the memorial. The bat could be subject to fireworks and aircraft noise, and could occur in areas subject to fire risk. ...However, wildfire effects are temporary, of low probability, and do not constitute incidental or purposeful take, as defined in the 2016 USFWS Programmatic Biological Opinion for the northern long-eared bat (USFWS 2016). The bats are sensitive to acoustics, but are likely to be in roosts and remain sheltered during the event.

Impacts to wilderness quality

There is no designated Wilderness within the boundaries of the memorial, but the designated USFS Black Elk Wilderness lies to the west of the memorial. No planned activities would occur in designated Wilderness under the preferred alternative (see Section 2.1, Alternative 1); however, the fireworks event may affect Wilderness qualities. The five qualities of Wilderness character, as defined in the Wilderness Act of 1964, are: (1) untrammeled; (2) undeveloped; (3) natural; (4) offers outstanding opportunities for solitude or primitive and unconfined recreation; and (5) other features of scientific, educational, scenic, or historical value. Of these, the preferred alternative may result in temporary impacts on opportunities for solitude from the fireworks event. Visitors camping or recreating in the Black Elk Wilderness may experience visual and acoustic disturbances from the event; however, these disturbances would last for 15 to 30 minutes. The NPS would minimize potential adverse impacts on the Wilderness experience for visitors by posting the event in advance.

While a 2016 study by the U.S. Geological Survey concluded that surface and groundwater at Mount Rushmore were probably polluted with a chemical common to rocket fuels and explosives by past fireworks display, the EA prepared for this year's event played down the threat of additional perchlorate contamination by noting the U.S. Environmental Protection Agency has been considering a move to bump up the allowable amount of the chemical in drinking water by more than three times, from 15 microgrms per liter to 56 micrograms per liter.

Perchlorate has been found to interfere with the function of the human thyroid gland.

A study released Wednesday in the journal Particle and Fibre Toxicology pointed out that the lead, copper, titanium, strontium, and other "toxins" that give fireworks their vibrant colors "also damage human cells and animal lungs."

"While many are careful to protect themselves from injury from explosions, our results suggest that inhaling firework smoke may cause longer-term damage, a risk that has been largely ignored," said Terry Gordon, PhD, a professor in the Department of Environmental Medicine at NYU Langone Health who was the study's senior author.

"Although people are only exposed to these substances for a short time each year, they are much more toxic than the pollutants we breathe every day," added Gordon.