I’m sure you have seen those appealing bottles of gourmet salt for sale in gourmet food stores. They come from all around the world in a variety of colors and types of crystals. Did you ever wonder what makes one pink, another gray and yet another brown? Probably not, but I did. Yea, I know, pretty geeky, but table salt, NaCl, is colorless. So I bought a dozen different brands, then we dissolved about 0.14gm in 50ml of 2% nitric acid and analyzed by ICPMS for metal content, in particular heavy metals that might be harmful to one’s health. The tables below list the salts tested and the results. Oh, we also tested normal table salt and reagent grade sodium chloride, NaCl.
Gourmet Salts analyzed
| Description | Source | Type | Color | Appearance |
|---|---|---|---|---|
| Cyprus Black Salt | Med. Sea | Sea | Dark Grey | 2-10mm crystals |
| Mediterranean Sea Salt | Med. Sea | Sea | White | 2-3mm crystals |
| Sel Gris De Guerande | France | ? | Light Grey | 1-3mm crystals |
| Alaea Hawaiian Sea Salt | Hawaii | Sea | Red Brown | 2-3mm crystals |
| Hawaii Kai Black Salt | Hawaii | Sea | Black | 1-3mm crystals |
| Murray River Pink Flake Salt | Australia | River | Light Pink/Beige | <2mm Flakes |
| HimalaSalt Primordial Sea Salt | Himalayas | ? | Pink to white | 2-10mm crystals |
| Sel de Mer | Israel | ? | White | 3-5mm crystals |
| Murray River Pink Flake Salt | Australia | River | Light Pink/Beige | <2mm Flakes |
| Kala Namak Black Mineral Salt | India | Mineral | Light Brown/Black | Fine powder |
| Chardonnay Oak Smoked Salt | France | Sea | Grey/Brown | Small crystals |
| Himalayan Pink Mineral Salt | Himalayas | Mineral | Light pink/white | Fine crystals |
Toxic Metals in Gourmet Salts (parts per million by weight)
| Metal | A | B | C | D | E | F | G |
|---|---|---|---|---|---|---|---|
| Cd | 0.055 | ND | ND | ND | ND | ND | 0.1 |
| Pb | 0.913 | 0.56 | 1.342 | 0.472 | 0.885 | 0.509 | 0.94 |
| Hg | 0.116 | 0.009 | ND | 0.159 | 0.114 | 0.071 | 0.075 |
| As | ND | ND | ND | ND | ND | ND | ND |
| Metal | H | I | J | K | L | Table Salt | Reagent NaCl |
|---|---|---|---|---|---|---|---|
| Cd | ND | ND | ND | 0.069 | ND | 0.007 | ND |
| Pb | 0.464 | 0.4 | 0.578 | 1.102 | 0.456 | 0.388 | 0.44 |
| Hg | 0.043 | 0.118 | 0.18 | 0.003 | 0.041 | ND | ND |
| As | ND | 0.016 | 0.1 | ND | ND | ND | ND |
Effect of Toxic Metals on Adults
As you can see the levels of heavy metals in these samples were very low. The concentration was only about one ppm for lead in several of the samples and the other heavy metals were generally at least an order of magnitude lower. But one has to watch out even at these low levels as heavy metals tend to be difficult for the body to eliminate and therefore they can accumulate over time.
- Lead: Is a cumulative poison and causes cancer reproductive problems.
- Cadmium: Causes hypertension, bone and joint aches and pains and damages the kidneys and liver.
- Mercury: Is the most toxic of all the heavy metals. Causes tiredness, loss of appetite and brain damage.
- Arsenic: Causes skin cancer, kidney and liver failure
So how much is too much? It is a very tough question so I’ll give you some information and let you decide. A number of sources list the allowable concentrations of heavy metals. But the key is the total quantity or weight of the heavy metal one takes in since one person might consume much more or less of a food, supplement or in the case here gourmet salt. Current recommendations are for one to limit their intake of sodium to 2400mg per day which equates to about a teaspoon, or 6gm of table salt. So our calculations will be based 6gm of salt, which is probably low for most people.
The table below lists the Allowable Daily Limit (ADL) of four heavy metals in micrograms per day, one microgram = 0.000001gm. We also list the maximum weight found of these metals equated to a 6 gm sample of the salt. Based on this, the last column shows the percent of the daily allowance that one would get from the 6gm intake of salt. As you can see salt would contribute low percents of these daily intakes but bear in mind this is only one source and all sources add up, so one must minimize each source as much as possible.
Allowable Daily Intake (ADL) of Heavy Metals (ug) (6 g Daily Serving)
| Element | Max Wt (ug) found in 6g sample | ADL | % ADL per Serving |
|---|---|---|---|
| Arsenic | 0.6 | 130 | 0.5 |
| Cadmium | 0.6 | 55 | 1.1 |
| Mercury | 1.08 | 8 | 13.5 |
| Lead | 8.06 | 50 | 16 |
www.fda.gov/Food/default.htm