On Tuesday, the U.S. Food and Drug Administration (FDA) issued a statement that announced it commissioned an investigation to evaluate metals, such as lead and arsenic, in tampons.

The FDA’s actions follow concerns about tampon safety after a recent study found metals in tampons during laboratory testing. The small pilot study tested 16 metals in 30 tampons from 14 tampon brands and 18 product lines from major online retailers and stores in the U.S., United Kingdom and Greece.

The study found small amounts of heavy metals, such as arsenic and lead, in organic and nonorganic tampons. Lead concentrations were higher in nonorganic tampons while arsenic was higher in organic tampons. No safe level of exposure to lead exists, according to the U.S. Environmental Protection Agency. CNN reported the average lead concentration in tampons was about 10 times higher than the maximum levels currently allowed in drinking water.

While the study found metals in some tampons, the study did not test whether metals are released from tampons when used. The study also did not test for metals being released, absorbed into the vaginal lining, and getting into the bloodstream during tampon use

FDA’s comprehensive review of the pilot study will provide a better understanding of the data currently available regarding the presence of chemicals in tampons and, importantly, any associated health effects of those chemicals. The FDA’s laboratory study will measure the amount of metals that come out of tampons under conditions that more closely mimic normal use. These initiatives will enable the FDA to complete a risk assessment of metals contained in tampons, based on a worst-case scenario of metal exposure.

The FDA will communicate its findings from the literature review and lab testing publicly when they are available and have been peer reviewed. The FDA will also continue monitoring these devices as part of its total product lifecycle approach to medical devices.

Before tampons can be legally sold in the U.S., they must meet FDA requirements for safety and effectiveness. Manufacturers must test the product and its component materials before, during, and after manufacturing. Before a product is allowed onto the market, biocompatibility testing is undertaken by the manufacturing company, which is part of safety testing, and is reviewed by the FDA prior to market authorization.

Southern California has three major wildfires burning, endangering tens of thousands of homes and other structures. The Bridge, Line, and Airport fires were fueled by a triple-digit heat wave that finally ended Wednesday.  

Already this year, California has seen nearly three times as much acreage burn as all of last year, and the state is only now entering the heart of its traditional fire season. So far this year, 6,078 wildfires have burned nearly 1 million acres and damage or destroyed 1,333 structures, according to Cal Fire.  

The Bridge Fire, which started Sunday in Angeles National Forest, had burned 47,904 acres by Wednesday, and is O% contained, Cal Fire reports. This fire has prompted evacuation orders for areas in Los Angeles and San Bernardino Counties and is currently the third largest fire of the year. The largest fire of the year, Park Fire, has burned 429,603 acres, and is California’s fourth largest fire of all time on record.

The Line Fire, which started on Sept. 5, is burning in the foothills of the San Bernardino National Forest, east of Los Angeles, and on Wednesday had burned 34,659 acres with 14% containment, according to Cal Fire. Some 65,600 structures are threatened by the fire, and evacuation orders are in place for several area communities, NBC News reports.

In California’s Orange and Riverside Counties, the Airport Fire has burned 22,376 acres since it started on Monday and is 0% contained.

Because of the state’s 16 active fires, on Tuesday, California Gov. Gavin Newsom mobilized nearly 6,000 boots on the ground along with 520 fire engines, 51 helicopters, 9 fixed-wing aircraft, and 141 water tankers to aid in combating the blazes.

In neighboring Nevada, the Davis Fire, which started 20 miles south of Reno on Saturday, has burned 5,824 acres in northern Nevada and was 31% contained as of Wednesday morning. On Sunday, Nevada Gov. Joe Lombardo declared a state of emergency due to the Davis Fire, which had already caused the evacuation of approximately 20,000 people from residential neighborhoods and businesses. On Wednesday, new evacuation warning areas extended into parts of South Reno.