Human cremation is a common practice, offering a meaningful method for final disposition. As people consider end-of-life choices, environmental effects are a growing concern. Understanding cremated remains, often called ashes, and their interaction with natural systems helps inform these decisions. This article explores the composition of human ashes, their potential environmental effects when dispersed, responsible scattering guidelines, and other disposition options that minimize environmental impact.
The Nature of Human Ashes
After cremation, human remains are transformed by high temperatures (1,400-1,800°F), which break down organic material. The resulting substance is not true “ash” like wood ash. Instead, it consists primarily of bone fragments pulverized into a coarse, gritty material, similar to sand.
The main chemical component of these remains is calcium phosphate, a mineral central to bone structure. Other elements like sulfate, potassium, sodium, and chloride are present in smaller amounts. Their concentrated form gives human ashes distinct chemical properties. Cremated remains are highly alkaline, with a pH level around 11 to 12.5, comparable to bleach. They also contain a notable amount of sodium.
Environmental Impact of Ash Dispersal
Scattering human ashes can affect the environment depending on location and quantity. On land, the high alkalinity and sodium content of cremated remains can disrupt soil chemistry. Untreated ashes can significantly raise soil pH, hindering plant nutrient absorption. High concentrations of ashes can be detrimental to plant growth, with potential for high mortality rates for seedlings. The sodium content can be hundreds to thousands of times higher than what most plants tolerate, potentially damaging plant tissues.
In aquatic environments, ash dispersal impact depends on the water body’s volume. Scattering ashes in large, open bodies like oceans results in minimal environmental effects due to rapid dilution. However, smaller, contained freshwater systems like lakes or rivers are more sensitive. The high concentration of calcium phosphate can alter water chemistry, including pH levels, which may affect aquatic life and plants.
In open marine environments, cremated remains are considered non-toxic and do not harm marine life as they disperse and settle. Ashes quickly settle from the air, posing no long-term airborne threat.
Guidelines for Responsible Scattering
Individuals choosing to scatter ashes in a natural setting can minimize environmental effects. Scattering remains widely, rather than in a single pile, helps dilute their concentration and allows gradual integration into the environment. This approach reduces the localized impact of the ashes’ high pH and mineral content.
Choosing appropriate locations for scattering is important. Select areas away from sensitive ecosystems, high-traffic public spaces, or direct water sources. Many national parks require permits for ash scattering, often specifying locations away from trails, roads, and at least 100 yards from waterways. Always obtain permission from landowners or relevant authorities, especially for public or protected lands, to ensure compliance and respect for the environment. Avoid leaving non-biodegradable containers or items at the site; biodegradable urns are available that break down naturally, releasing ashes gradually.
Eco-Friendly Alternatives for Human Remains
Beyond traditional cremation and ash scattering, several eco-friendly options exist for human remains. Green burial, or natural burial, involves interring the body without embalming chemicals, in biodegradable materials like a shroud or simple casket, directly into the earth. This method allows natural decomposition, returning nutrients to the soil and reducing the ecological footprint of conventional burials. Green burial sites often prioritize the conservation and restoration of natural habitats.
Aquamation, or alkaline hydrolysis, offers a water-based alternative to flame cremation. This process uses water and alkaline chemicals to accelerate natural decomposition, yielding a sterile liquid and bone fragments. Aquamation uses less energy and produces fewer greenhouse gas emissions than traditional cremation, offering a reduced environmental impact. The resulting bone fragments are processed into a substance similar to cremated ashes.
Natural organic reduction, also called human composting, transforms human remains into nutrient-rich soil. This process places the body with organic materials like wood chips and straw in a controlled environment. Naturally occurring microbes facilitate decomposition over weeks. The resulting soil can be used for conservation efforts or in memorial gardens, contributing to land restoration and avoiding carbon emissions and chemical use. This option can also sequester carbon, actively contributing to environmental health.