1. Bioaccumulation and
Biomagnification

2. Bioaccumulation
Toxins are entering our ecosystems everyday:
• Mercury
• PCBs (coolants, adhesives, lubricants, sealants,
flame retardants)
• Pesticides (like DDT)

3. Bioaccumulation
After these toxins have been taken-up by plants or
animals, they can not be easily excreted or eliminated
– they often stay in the animals until they die.

4. Bioaccumulation
This means that as
the organism ages
and continues to
eat, the toxins
accumulate in their
bodies. This is called
bioaccumulation.

5. Bioaccumulation
Many of these toxins collect in the adipose tissue
(fat cells). This means that larger people will often
accumulate more toxins.

6. Bioamplification
Bioamplification refers to the large increases of
toxins found in organisms at higher trophic levels.

7. Bioamplification
It only takes a very small concentration of toxin to
harm an organism. These concentrations are
measured in ppm and ppb.
ppm = parts per million
ppb = parts per billion

8. Bioamplification
(1 000 000 L)
1 ppb
1 ppm
(1 000 L) 1 mL

9. The Bioaccumulation Factor
~ 15000 ppb
~ 3300 ppb
~ 25 ppb
Ecologists can calculate ~ 1.6 ppb
an organism's
bioaccumulation factor
using the formula:
Bioaccumulation factor = Toxin Concentration in Organism
Toxin Concentration in Environment

10. The Bioaccumulation Factor
For example, if a smelt has a DDT concentration of 1.8 ppm
and its habitat has a DDT concentration of 0.005 ppm, what
is the smelt's Bioaccumulation Factor?
Bioaccumulation factor = Toxin Concentration in Organism
Toxin Concentration in Environment
Bioaccumulation factor = 1.8 ppm
0.005 ppm
= 360