¿ìè¶ÌÊÓƵ

Last Word is ¿ìè¶ÌÊÓƵ’s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com

How can I ensure that most of my body is used after my death and what is left over can be turned into something like compost?

Stephen Johnson
Eugene, Oregon, US

There are many ways in which your body can be useful after your death. First, there is organ donation, and there is a continuous need for human organs. There is no age limit for becoming a donor, and even older bodies still have useful organs.

In addition, science has a perpetual need for human bodies for research. In the US, there are state and national organisations that take donations of human bodies and place them where they are needed. After the body is used for science, the remains can be returned for burial or the person’s family can receive cremated remains. Arrangements are best made in advance with such organisations.

Finally, in around a dozen US states, including where I live in Oregon, there are companies that will actually compost your body and return soil to your family. In many cases, the family will only want a portion of the soil since composting a human body produces around a cubic yard (0.75 cubic metres) of soil, enough for a small truck load.

In around a dozen US states, there are companies that will actually compost your body and return soil to your family

The remaining soil can then be used in gardens, natural areas or for conservation projects. In some cases, it may be possible to compost someone’s remains after their body has been used for scientific research. However, this depends on what use was made of the body and the possible toxins in the remains.

Katrina Spade
Seattle, Washington, US

Human composting is a relatively new death care option developed by my company, Recompose. It mimics the process that happens on the forest floor, where sticks, leaves and other organic materials decompose naturally to form the basis for all life on Earth – soil.

Here’s how human composting works at Recompose: when someone dies, their family calls us to plan logistics and a memorial service if they choose. Once our team has received the person’s body, we lay a carefully calibrated mixture of wood chips, alfalfa and straw into a stainless steel composting vessel. We place the person’s body on top of that mixture and cover it with more of the same. A basic fan system pulls air through each vessel – this is an aerobic process, meaning oxygen is a necessary ingredient. Each vessel has temperature probes telling our team how warm the material is becoming because of all the microbial activity. About once a week, we rotate each vessel slowly, ensuring, like in any good composting process, that there is plenty of oxygen. Most bodies take between 30 and 40 days to transform into soil. It then takes a few more weeks for that soil to cure. Once it’s ready, friends and family can come to Recompose to pick up the soil for use in their gardens, or they may decide to donate it to our Land Program for use on conservation projects. Whether it is donated or used by loved ones, the soil is nutrient-rich and ready to grow new life.

To answer this question – or ask a new one – email lastword@newscientist.com.

Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.

¿ìè¶ÌÊÓƵ retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.

Terms and conditions apply.

Ìý