of the unintended consequences of the modern chemical revolution
has been world-wide dispersal of contaminants. No ecosystem has
been left untouched. No human has been born since the
middle of the 20th century without some exposure, in the womb, to
hormonally-active synthetic compounds. Much of the dispersal of
the contaminants is by atmospheric or oceanic currents. (See OSF
Chapter 6, To the ends of the earth, for a detailed description.)
Even animal migrations play a role (see below).
result is an uncontrolled, largely unmonitored experiment playing
out at global scale. Several recent studies bring this home vividly.
children sampled in a study of the presence of phthalate metabolites
in urine contained at least 3 metabolites, with levels higher than
those that had been reported in a study of phthalate urinary metabolites
in adults. More...
Nonylphenols were discovered in the late 1980s to be estrogen mimics.
Now a team of German scientists reports that nonylphenols are present
in a wide variety of foods bought in German marketplaces, everything
from gooseberry marmalade to liver sausage to chocolate crumble
to doublecream cheese
and baby foods. All samples exampled contained measurable amounts
of nonylphenols. More...
sulfonate--has emerged as a new type of persistent, organic pollutant
that binds to proteins rather than accumulating in fatty tissues.
The widespread nature of PFOS contamination was missed for a long
time, even though the compound has been in commercial use (in products
like 3M's Scotchgard) since the 1950s. New studies are documenting
PFOS contamination in many living organisms around the world, including
(pdf file), polar
bears and bald eagles.
are popping up all over. These are polybrominated flame retardants,
used in many different types of plastics and plastic-containing
products. They are powerful thyroid disruptors that are both persistent
and bioaccumulative. It turns out that when they leach out of the
plastics in which they are put, they quickly find their way into
the biosphere. One prominent pathway is polyurethane foam.
When it degrades, the most toxic form of PBDEs (penta-BDE) escapes.
In the US, not only is there passive transport of PBDEs via water
and air currents, but PBDEs are also actively transported and dispersed
because they are a prominent contaminant in sewage sludge, which
is sprayed onto farmers' fields. This is looney!! Since
the 1970s, PBDEs have increased more than 50-fold in breast milk.
More on PBDEs
October 2000. In early 2001 the US Centers for Disease Control
will release results of the most ambitious effort ever undertaken
to measure exposures of Americans to chemical contaminants. They're
calling it the National Exposure Report Card. It will will
tell scientists and the public how many Americans -- and which ones
-- have unusually high levels of lead, pesticides and other undesirable
substances in their blood. Tests on 5000 people will include
measurements for 25 substances, including heavy metals such
as lead, cadmium and mercury, tobacco products, organophosphate
pesticides such as chlorpyrifos and malathion, phthalates, dioxins
and PCBs. Tests will be repeated each year to track trends in the
a 2003 update of this report...
October 2000. In research conducted for the North
American Commission for Environmental Cooperation, scientists
from Queens University, New York, trace the pathway of dioxin falling
on arctic Canada back to its sources. Most comes from the US
(mostly from municipal solid waste incinerators, backyard trash burning,
cement kilns burning hazardous waste, medical waste incinerators,
secondary copper smelters and iron sintering plants), with less from
Canada and some from Mexico. The research team, led by Dr.
Barry Commoner, employed state-of-the-art computer modeling tools
to identify the dioxin sources. More...
2000. Atmospheric currents carry a soup of pollutants eastward across
the Pacific from Asia to North America, contaminating local ecosystems
and creating health risks for wildlife and humans alike. More...
study of amniotic fluid in California indicates two out of three fetuses
encounter elevated levels of DDE and HCH in the womb. More...
study by the US Centers for Disease Control documents significant,
contamination in Americans. Among the highest concentrations were
observed in women of child-bearing age. More...
to data released in July 2000, concentrations of PCB and PCB-related
contaminants are up to 70x higher in Inuit residents of far northern
Canada than in blood samples taken from southern Canada. More...
altitude alpine lakes in the Alps are contaminated by DDT being used
for malaria control in the tropics. More...
DW. 2000. Trends in usage and global redistribution of pesticides
(Abstract A41). In Science in an Uncertain Millennium, R.
Paulson, ed. Washington, D.C. 2000 Annual Meeting of the American
Association for the Advancement of Science. Washington, DC. February
reported in a paper given at the AAAS annual meeting that persistent
organochlorine contaminants that had been deposited in glacial snow
are being liberated by melting. The implication of this work is
that as climate disruption warms the Earth, rising temperatures
will volatilize contaminants that had been trapped in what amounted
to cold storage. These compounds are thus more likely to enter the
Boer, J, PG Wester, HJC Klamer, WP Lewis and JP Boon. 1998. Do
flame retardants threaten ocean life? Nature 394:28-29.
to de Boer et al., brominated flame retardants "are used at
relatively high concentrations in electronic equipment such as computers
and television sets, in textiles, cars and in many other applications."
In this study they report that two groups of these compounds, polybrominated
biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs), are
found in multiple species of marine life, including sperm whales.
presence of these compounds in sperm whales, which feed in the deep
ocean, "indicates that the compounds have reached deep ocean
waters, as sperm whales are not usually found in shelf seas."
found "relatively high PBDE concentrations in a whitebeaked
dolphin (>7 mg/kg) and in harbour seals (>1 mg/kg), which had been
feeding in the North Sea and the Wadden Sea. PBDE levels in dolphins
and seals indicate that ongoing industrial production of PBDEs
may create an environmental problem similar to that caused by PCBs,
which have been found at concentrations up to 128 mg/kg in marine
they performed on persistence indicate that PBDEs may be even more
persistent in the environment than PCBs.
conclude by observing: "The presence of PBBs and PBDEs in sperm
whales, the high levels of particularly PBDEs in seals and dolphins,
and the on-going industrial production of these compounds suggest
that an environmental problem may be on its way."
study released in Japan in June 2000 reports high levels of PBDEs
in people. More...
transport nutrients and pollutants upstream during their migrations,
causing accumulation of persistent bioaccumulative contaminants in
remote lakes. More...
JM, DW Schindler, DCG Muir, LE Kimpes, DB Donald and B Rosenberg.
1998. Accumulation of persistent organochlorine compounds in mountains
of western Canada. Nature 395:585-588.
et al. report that mountain regions in British Columbia far
from sources of contamination accumulate organochlorine pesticides
and PCBs in their snowpacks.
that they sampled showed a 10- to 100-fold increase between
700 and 3,100 meters in altitude (right, from Blaise et al.).
Atmospheric deposition appears to be the only process that
"can provide a plausible explanation for the observed contamination
of fish in high-altitude Canadian lakes."
raise important questions about water supplies for cities
that depend upon snow pack accumulations, especially those dependent
upon water supplies from high mountains. "For example, cities
like Denver and Mexico City derive their water supply
from snowmelt on mountains over 3,000 m high. They are also much
closer to industrial and agricultural sources of contaminants in
areas that reach summer temperatures 5-10° C warmer than those
of western Canada. The effect of cold condensation on the fate of
organochlorine in these areas remains unknown, but is likely to
result in more pronounced accumulation of toxic compounds than we
have observed in our study area."
SL and RA Hites. 1995. Global distribution of persistent organochlorine
compounds. Science 269:1851-1854.
and Hites report on the global distribution of 22 organochlorine
compounds in more than 200 tree bark samples from 90 sites around
the world. High concentrations of some of the studied compounds
were found in developed and developing countries alike. Those compounds
that are relatively more volatile tend to have greater global distribution.
concentrations of organochlorine compounds were measured in tree
bark from the United States, Europe, India, the Middle East, Japan,
Brazil, Australia, Taiwan, South Korea, and Russia.
from agricultural areas of the midwestern and eastern United States
showed high concentrations of contaminants, as did samples from
agricultural areas in California and the southwestern United States.
In Europe, contamination was consistently high in parts of Germany,
Romania, Belgium the Netherlands and Denmark. In Japan, contamination
was consistently high in and around Tokyo and lower in Hokkaido.
organochlorine compounds found in the highest concentrations were
the HCHs, the endosulfans, and p,p'-DDE (a degradation product