|
While consumers are well aware of the health benefits of
marine-derived omega-3 fatty acids, they are equally concerned with
potential contamination issues.
Environmental contaminants are chemicals that enter the
ecosystem as a result of industrial activity. These compounds
bioaccumulate in the fatty tissues of fish, meaning that oil
derived from these tissues may contain high concentrations of
environmental contaminants.
Heavy metals
Heavy metals such as arsenic, cadmium, lead and mercury are
naturally-occuring substances that are used in a variety of
industrial processes. Heavy metals are not easily broken down
and therefore are found throughout the environment at low
levels. Exposure to heavy metals can occur in a number of
ways, including from the diet.
Lead is highly toxic, particularly for infants
and children because their tissues and organs are still rapidly
developing. Adverse effects include impaired cardiovascular,
gastrointestinal, reproductive and nervous system functioning.
Mercury exists as three major forms: elemental,
inorganic and organic. The organic form, also referred
to as methyl mercury, tends to be present in certain fish, wild
game and marine mammals. Toxic effects of methyl mercury
exposure include cognitive impairments, nervous system dysfunction,
blindness, lack of coordination, deafness and even death.
Arsenic (as both organic and inorganic forms)
is present at low levels in both animal- and plant-based
foods. Long-term exposure to inorganic arsenic has been
linked to the development of certain cancers. Short-term
exposure to inorganic arsenic can cause skin
and gastrointestinal problems as well as numbness of the hands
and feet.
Cadmium is a highly toxic metal used
in industrial manufacturing. Exposure to cadium in the
workplace is commonly through inhalation of dust particles, but
cadmium is also present in the food supply. Excess cadmium
ingestion can cause severe and irreversible liver and
kidney damage and even death. Cadmium is also a known
carcinogen.
Polychlorinated biphenyls
(PCBs)
Although the use of PCBs in industrial manufacturing has
been banned in North America for more than 30 years, they
are still present in the environment at trace levels due to their
inability to break down. The primary route of human exposure
is through the diet, particularly in animals high in the
food chain. For example, consumption of large amounts of
certain fish, wild game and marine mammals can result in excess
exposure.
PCBs have negative health effects including skin problems,
muscle spasms, chronic bronchitis and nervous system disorders.
Dioxins and furans
These toxic compounds are produced from industrial
combustion processes such as metallurgy, fuel combustion and waste
incineration and are found in low levels in water, air and
soil. Due to their presence in the environment, dioxins
and furans are found in foods, particularly in the
fatty tissues of animal-based products such as meat
and fish.
Exposure to dioxins and furans has been linked to a number of
adverse health effects including skin, liver and immune system
problems, endocrine and reproductive disruptions and the
development of certain cancers.
|
