Fighting Fungus – Know Your Enemy

by April K. Sievert, GBL Director

Hot and rainy summers are certainly hard on the climate within our repository! In order to preserve the artifacts collected 80 years ago by Glenn A. Black at the Angel Mounds site, we need to contend with environmentally-related dangers to both staff and stuff. One of these is mold, tiny fungal bodies and spores that feed off organic materials. Molds love to grow where its dark and moist, and the inside of a box of archaeological bone may be ideal places under rising heat and humidity. Normally, as GBL Director, I don’t get the chance to get down and dirty, so I was happy to be able to arm myself with protective gear and start to figure out what we are dealing with .

April Sievert starting some mold research

We discovered serious mold problems at around the same time that we received news that we were awarded funding for Curating Angel Mounds, through the Save America’s Treasures program of the National Park Service, administered by the Institute for Museum and Library Services (IMLS). The first task was to have an air quality test done. Results of this test, which is facilitated by IU’s Environmental Health and Safety Department, shows higher levels of a common mold family—Aspergillus/Penicillium— in the air in our Angel Mounds Repository. The report indicates mold likely originating from within the room itself. This mold was likely being generated by moldy materials, most likely the acidic brown paper bags used for artifacts, some of which show both water damage and signs of mold (molds love acidic materials).

Test results on mold identified in the air the Angel Curation room

Mold produces spores from tiny branching filaments called hyphae. The mold can be inactive (dried spores that look like dust and can remain dormant for years) or active, meaning that the hyphae are happily making new spores. The hyphae are like tiny straws that suck water out of the substrate (whatever the mold is growing on) so that they can grow and make more spores. Active mold presents as smeary, fluffy, or hairy patches on surfaces. Molds grow well at temperatures between 60-90° F and RH above 65%. We deployed a large noisy air scrubber to remove the spores from the air, and extra dehumidifiers to bring the humidity down.

There are two quite different kinds of mold on the bags and artifacts from Angel Mounds that are visible with the naked eye. One presents as a white deposit adhering to a scratch on the bone surface.

White deposits in crevice on faunal bone

The network of hyphae and spores become visible under high-power magnification using the polarizing filter on our metallurgical microscope. White deposits on at 500x magnification show a blurry mass of filaments the represent actively growing mold.

White mold hyphae

The white mold is consistent with the Aspergillus/Penicillium group and appears to like cuts or crevices in the bone cortex. Softer spongier bone provides easily accessible nutrients for the fungus. A very different brown mold that flourishes on a small proportion of bags shows up as fuzzy dots.

Bag fragment from 1939 showing brown active mold

Bones within these bags sport dense patches of hyphae with dark brown spores. After initial cleaning, the location still had a tenacious colony of brown spores.

Brown mold with well-developed fruiting bodies and spores (500x magnification)
Mold colony after one cleaning with alcohol (500x magnification)

The clearly-seen spores are about 10 microns long and 6 microns wide, appear iridescent under polarized light, and are quite lovely. We’ll be sending samples of these beauties to a lab for more precise identification. So, stay tuned for more on mold, and the conservation treatment we are using!

Angel Rehousing Project, Part 5

Part 5 of Amanda’s Angel Rehousing Project blog series

by Amanda Pavot

I have returned with news!

First, this is going to be my last blog post of the semester. However(!), the current plan is to continue to make blog posts about the project as it goes on. It’s just going to be different people writing. Maybe we’ll get more perspectives other than mine! Keep checking the blog for more updates!

More importantly, the Rehousing has started! It’s being divided into a couple of phases, those phases being “sort out the moldy bone boxes” and then “do everything else.”

~Issues in Curation~

Remember last post when I said that our NAGPRA team was pulling out AFOs and going through faunal remains to ensure that all sacred items and human remains are accounted for? Also, remember waaay back when I said that some of the boxes of artifacts have mold in them?

After opening boxes that had faunal remains in order to go through them, many of those boxes were found to have mold in them. Before our NAGPRA team can sort through those bones, they need to be cleaned up and rehoused into temporary bags and boxes. Only then can they be sorted through. Because it’s Very Important to get this done, cleaning up the moldy bone boxes is the priority right now. So here’s how it works:

First, we put on our respirators and nitrile gloves. That’s very important. Then we pull one of the moldy boxes. We take out one of the bags and look up the information written on the bag to find it in our digital database. Then we take the bones out of the bag, count them, vacuum off any mold (using a special attachment on the vacuum with the HEPA filter, which I think is cooler than it probably really is. The mold just comes right off, though!), and then weigh them. We get a new, archival-quality bag, write the information from the old bag onto the new one along with quantity and weight, and put the bones into the new bag. We also update the information in the database –for example, sometimes the number of artifacts in the bags and the number the database says we should have in those bags are different. Put the bag into a new box, move on to the next bag!

I left out a lot of the nitty-gritty details, but that’s basically how it works. We’re working in teams of two, one on a laptop with the database and one on the vacuum. When we finally finish all of the moldy bones, we’ll move on to the rest of the bulk collection. We’ll be training more people soon, and with more people we’ll be able to plow right through these boxes this summer!

I want to thank everyone who’s read these posts and has followed along so far. So: thank you! I’m looking forward to where this project is headed, and I hope you all are interested in it, too. I may be making some posts in the future, but, until then, have a great summer!


In September 2018, the GBL was awarded a Save America’s Treasures grant to rehabilitate and rehouse about 2.8 million artifacts from Angel Mounds over the next 3 years. These grants are administered by the National Park Service in partnership with the Institute of Museum and Library Services.

This “Curating Angel” project will allow us to provide safe, long-term preservation of the artifacts and associated documentation from archaeological work at Angel Mounds and make these collections more accessible for research and education.

More about IMLS

The Institute of Museum and Library Services is the primary source of federal support for the nation’s libraries and museums. We advance, support, and empower America’s museums, libraries, and related organizations through grantmaking, research, and policy development. Our vision is a nation where museums and libraries work together to transform the lives of individuals and communities. To learn more, visit www.imls.gov and follow us on Facebook and Twitter.

(The views, findings, conclusions or recommendations expressed in this blog post do not necessarily represent those of the Institute of Museum and Library Services.)

Angel Rehousing Project, Part 1

The first blog post by Amanda Pavot about the ongoing Angel Rehousing project.

by Amanda Pavot

Hello everyone! This is Amanda Pavot, and about once a week for the next month or so I’m going to be posting updates about our Angel Rehousing project, which is starting soon. But some things first:

What the rehousing is

Getting the artifacts of the Angel Mounds collection out of their current bags and boxes, and putting them in archival-quality bags and boxes. It will help conserve them, but also most of them are in the original brown paper bags that they were put in directly after being taken out of the ground decades ago (literally 60-70+ years ago for a lot of them!), and that’s just gross. And there are around 2.5 million individual artifacts that need to be rehoused, so this is a big project.

Preparation for something of this scale involves a lot of logistics. Everything from “What room are the artifacts going to be rehoused in?” and “How many artifacts need to be re-housed per day in order to finish in the time we need to do this?” to “How do we budget this?” Hiring people, needing to schedule respirator fittings (more on that later), buying the bags and boxes needed, and so many other tasks need to be completed and questions answered before the project can even start.

But those are all problems for people above me. I’m just a grunt, which means most of my preparation has been to finish all of these other small projects and tie up other loose ends before this big project starts. But that’s for another blog post. The task done in preparation that I’m going to talk about today is in a little segment I’m going to call:

~Issues in Curation~

Mold! It’s there. In the room that the Angel collection is currently stored in. In the boxes that the artifacts are currently stored in. It should go unsaid that this is Not a Good Thing, but what do those working in a museum have to do in a situation like this? How does this affect the project?

There have been some delays in starting this project, this being one of the reasons. Originally, there was a plan to do the actual rehousing of the artifacts in the archives, which is next to the Angel Room. This is because there is a nice big table in the archives that would fit several people + boxes + artifacts, and also some computers if needed, and it would just be the kind of place to work on this project. But with the whole mold revelation, plans on how the rehousing was going to work had to be remade. Disturbing of the artifacts has to be confined to the Angel Room in order to help contain the mold, but it also has available space to work. So now not only do we have to decide how working in a different and much more confined space is going to be done, we also have mold cleanup to worry about. (Though again, most of those decisions I don’t have to worry about; but as one of the people doing the rehousing, I’ll be helping refine some strategies since I’ll actually be working in there).

Mold mitigation and cleaning affected artifacts is going to need to be taken into account. Cleaning the room itself (vacuuming, big expensive air scrubber, etc.) is also a factor that wasn’t there before. So is the protection of anyone working in there.

Last week was Respirator Fitting Time! Which I didn’t realize was a thing, though it makes sense in hindsight. Also training! To comply with OSHA standards, there was an official University training module we had to do online, plus a health form we had to fill out. Then someone from IU EHS (Indiana University Environmental Health Services) came over to help us with fitting. The respirators that we’re going to use are the ones that look a lot like medical face masks except they filter bad stuff like mold, so they need to be fitted to make sure they properly seal to your face. The model that we have didn’t fit the face shape of a couple of people, so we’ll be fitted for a different model eventually, but the one we tried fit me! So that means I’ll probably get to be one of the people to vacuum off the tops of the hundreds of cardboard boxes in the Angel Room, which is the next project that needs to be done before rehousing can get started. Yay!

Thanks for reading this far! I’ll keep posting more updates and changes in this project through the end of the semester. I hope that anyone who reads this will gain a little insight into what it’s like to work in a museum or other institution that houses large collections of artifacts like these.


In September 2018, the GBL was awarded a Save America’s Treasures grant to rehabilitate and rehouse about 2.8 million artifacts from Angel Mounds over the next 3 years. These grants are administered by the National Park Service in partnership with the Institute of Museum and Library Services.

This “Curating Angel” project will allow us to provide safe, long-term preservation of the artifacts and associated documentation from archaeological work at Angel Mounds and make these collections more accessible for research and education.

More about IMLS

The Institute of Museum and Library Services is the primary source of federal support for the nation’s libraries and museums. We advance, support, and empower America’s museums, libraries, and related organizations through grantmaking, research, and policy development. Our vision is a nation where museums and libraries work together to transform the lives of individuals and communities. To learn more, visit www.imls.gov and follow us on Facebook and Twitter.

(The views, findings, conclusions or recommendations expressed in this blog post do not necessarily represent those of the Institute of Museum and Library Services.)