Initial Publication Date: December 13, 2012

Chromium and its negative effects on the environment

Author: Charles Sneddon

This case study is part of a collection of pages developed by students in the 2012 introductory-level Geology and Human Health course in the Department of Earth Sciences, Montana State University. Learn more about this project.

Chromium comes in a plethora of forms and shapes in nature; it is a naturally occurring element (Atomic Mass #24), and can be both helpful and harmful to human health and the environment.

Introduction

Chromium is used mainly in metal alloys such as metal-ceramics, stainless steel, and is used as chrome plating. It has high value in the industrial world because it can be polished to a mirror-like finish, and provides a durable, highly rust resistant coating, for heavy applications. On the flip side, chromium can also provide health benefits to humans.

Sources of Chromium

Chromium is mined in different countries around the world (such as South Africa, Zimbabwe, Finland, India, Kazakihstan and the Philippines) as the naturally occurring form, chromate ore (FeCr₂O₄). Chromium is unstable in an oxygenated environment and, when exposed to air, immediately produces an oxide layer which is impermeable to further oxygen contamination.

Transport of Chromium into the Environment

Chromium enters the environment through both natural processes and human activities. Increases in Chromium III are due to leather, textile, and steel manufacturing; Chromium VI enters the environment through some of the same channels such as leather and textile manufacturing, but also due to industrial applications such as electro painting and chemical manufacturing. Groundwater contamination may occur due to seepage from chromate mines or improper disposal of mining tools and supplies, and improper disposal of industrial manufacturing equipment.

Bioavailability

Chromium can affect the air quality through coal manufacturing, which eventally can lead to water or soil contamination. Water contamination is fairly limited to surface water, and will not affect groundwater because chromium strongly attaches to soil and is generally contained within the silt layer surrounding or withing the groundwater reservoir. Water contaminated with chromium will not build up in fish when consumed, but will accumulate on the gills, thus, causing negative health effects for aquatic animals; chromium uptake results in increased mortality rates in fish due to contamination.

When consumed by animals, the effects can include "respiratory problems, a lower ability to fight disease, birth defects, infertility and tumor formation." (LennTech)

Impacts on Human Health

This pathogen is a mutagen, carcinogen, etc. It is concentrated in bone, blood, organs....

What are the tolerances? What is toxic, what is lethal?

Chromium VI (hexavalent chromium) is considered carcinogenic only to animals in certain circumstances at this point; chromium in general is currently not classified as a carcinogen as the OSHA and is fairly unregulated, but is considered toxic, level 3. While chromium III is essential for regular operation of human vascular and metabolic systems as well as combating diabetes, too much chromium III may result in severe skin rash, or other more serious symptoms.

Chromium VI is the most dangerous form of chromium and may cause health problems including: allergic reactions, skin rash, nose irritations and nosebleed, ulsers, weakened immune system, genetic material alteration, kidney and liver damage, and may even go as far as death of the individual.

There is, however, no established limit for human consumption of chromium III. Individulals have been recorded as consuming 1000mg daily for elongated periods with no negative effects; but, as with all minerals our body needs, too much consumption may result in poisoning.

Prevention or Mitigation

There are currently no standards or regulations regarding hazard mitigation. Water purification is completely optional, but active carbon and ion exchanging filtering methods are both very effective in eliminating chromium contamination.