AN OVERVIEW OF MINERALS TOXICITY Written by RDG, 2014 Copyright © 2014 - 2020, RDG. All rights reserved. First published electronically November 2014. Last updated December 19, 2020. Disclaimer: This article is not intended as an authoritative text. The author cannot be held responsible for your safety. TABLE OF CONTENTS 1.INTRODUCTION …................................................................................................................. 3 1.1.Why discuss the toxicity of minerals …....................................................................................3 1.2.A few basic notions of toxicology …........................................................................................ 3 1.2.1.Dose …...................................................................................................................................3 1.2.2.Bioavailability …................................................................................................................... 3 1.2.3.Toxicity class, Acute toxicity, and Median lethal dose …......................................................3 1.2.4.Chronic toxicity …................................................................................................................. 4 1.2.5.Carcinogenic, Mutagenic, Reprotoxic …...............................................................................4 1.3.Risk assessment ….................................................................................................................... 4 2.TOXICITY OF MINERALS …................................................................................................ 5 2.1.Radiotoxicity …........................................................................................................................ 5 2.2.Physical toxicants …................................................................................................................. 5 2.2.1.Coal …....................................................................................................................................5 2.2.2.Asbestos ….............................................................................................................................5 2.2.3.Crystalline silica …................................................................................................................ 6 2.3.Chemical toxicants …............................................................................................................... 6 2.3.1.Acute toxicity of elements and their inorganic compounds ….............................................. 6 2.3.2.Chronic toxicity of elements and their inorganic compounds …...........................................7 2.3.3.Acute and chronic toxicity in organic compounds …............................................................ 7 3.ACUTE TOXICITY OF MINERALS BY ORAL ROUTE …............................................... 9 3.1.Mercury …................................................................................................................................ 9 3.2.Selenium …............................................................................................................................... 9 3.3.Arsenic …..................................................................................................................................10 1 3.4.Phosphorus …........................................................................................................................... 11 3.5.Thallium …............................................................................................................................... 11 3.6.Tellurium ….............................................................................................................................. 11 3.7.Vanadium …..............................................................................................................................11 3.8.Chromium ….............................................................................................................................12 3.9.Fluorine ….................................................................................................................................12 3.10.Cadmium …............................................................................................................................ 13 3.11.Beryllium …............................................................................................................................ 13 3.12.Cobalt …................................................................................................................................. 13 3.13.Nickel …................................................................................................................................. 13 3.14.Barium …................................................................................................................................ 13 3.15.Copper …................................................................................................................................ 14 3.16.Radium …............................................................................................................................... 14 3.17.Uranium and Thorium …........................................................................................................ 14 3.18.Lead ….................................................................................................................................... 15 3.19.Antimony …............................................................................................................................15 3.20.Manganese …..........................................................................................................................15 4.SAFETY CONSIDERATIONS …............................................................................................ 16 4.1.Basic warnings …......................................................................................................................16 4.2.Extended safety procedures for handling and storage …..........................................................20 4.2.1.Asbestiform minerals ….........................................................................................................20 4.2.2.Preventing silicosis …............................................................................................................20 4.2.3.Moderately toxic minerals ….................................................................................................21 4.2.4.Toxic and highly toxic minerals …........................................................................................ 21 4.2.5.Radioactive minerals …......................................................................................................... 21 4.3.Hazardous chemical reactions when cleaning minerals with acids …......................................23 5.CONCLUSIONS …....................................................................................................................24 6.HAPPIER PERSPECTIVES …................................................................................................24 2 1.INTRODUCTION 1.1. Why discuss the toxicity of minerals? Just like optical properties (how the mineral affects light), we can also look at biological activity (how the mineral affects living organisms) as another intrinsic property of a mineral. As such, toxic, medicinal or nutritive properties of minerals make another scientifically meaningful topic to discuss: when mineralogy meets biology! Furthermore, the question of mineral toxicity is recurrent amongst beginner collectors, and this amateur study will try to approach it on the basis of concrete toxicological data. However, in order to avoid any overreacting to this article, let's immediately make it clear that, with only a little bit of common sense, building a mineral collection remains quite a safe hobby! 1.2. A few basic notions of toxicology: 1.2.1. Dose: An important principle of toxicology is that almost any chemical substance can be harmful if the dose (i.e. the administered amount) is high enough. Which is commonly translated as "the dose makes the poison". While toxicity largely depends on the dose, other important factors to be taken into consideration include the dose-time relationship (as frequency and duration of exposure), and the route of exposure (i.e. oral, dermal, inhalation). 1.2.2. Bioavailability: Bioavailability refers to the extent to which an administered dose will reach the systemic circulation (thereby accessing the site of action). Hydrophobicity, pKa, and solubility of the compound will influence its bioavailability. 1.2.3. Toxicity class, Acute toxicity, and Median lethal dose: The Toxicity Class of a compound is a classification system based on acute toxicity. Acute toxicity represents the toxic potential of a compound on the short-term. That is its capacity to produce harmful effects relatively soon after oral or cutaneous administration (as a single dose), or after a 4 hours exposure to the compound in air. 'Relatively soon' is usually defined as minutes, hours (up to 24h), or days (up to about two weeks), but rarely more. The acute toxicity of a compound is represented by its Median Lethal Dose, which is the dose that kills 50% of the tested animals (most often rats or mice). It is written LD50 for oral or cutaneous exposure (as mg/kg of body weight), and written LC50 for inhalation (as mg/m3 of air for solids, or as ppm for gases). So, comparing