Found in these people:
Found in these locations:
Laboratory animals. CDFs cause toxicity to many organ systems including the liver, kidney, adrenal, gastrointestinal tract, urinary tract, reproductive tract and neurological system. Specific reproductive effect includes testicular toxicity, decreased testicular testosterone levels and inhibition of ovulation. Neurological effects include decreased activity and tremors at high doses. CDFs also cause anemia, altered lipid metabolism, reduced muscle mass ("wasting syndrome") and altered immunological effect. One of the most visible effects of CDF exposure are skin and nail abnormalities, including nail loss, nail hemorrhage, skin lesions, absent or atrophied sebaceous glands, loss of eyelashes and fingernails. Fetal exposure to CDFs cause placental lesions, kidney toxicity, fetal mortality, low birth weight, cleft palate, decreased thymus and lung weight, altered bone development and liver enzyme activity (ATSDR 1994b).
Humans. Most of what we know about CDF toxicity in humans comes from the poisoning of rice oil with PCBs in Japan (Yusho) in 1968 and Taiwan (Yu-Cheng) in 1978. The CDFs were produced when the PCB contaminated rice oil was heated before contamination and during cooking. The "Yusho and Yu-Cheng" patients developed a variety of symptoms, including: headaches; vomiting; diarrhea; anemia; skin anomalies (such as acne and increased pigmentation and inflammation); numbness; weakness; limb pain associated with nerve damage; decreased sensitivity to pain; decreased sensory nerve conduction velocity; irregular menstrual cycles; increased incidence of respiratory infections; decreased resistance to illness; increased triglyceride levels; liver toxicity and eye inflammation or discharge. Developmental effects include low birth weight, premature birth, hyperpigmentation of the skin and nails, deformed nails, eye inflammation, acne, pneumonia and bronchitis in newborns, delayed development and decreased IQ (ATSDR 1994b). A relatively recent study suggests that prenatal exposure to the toxic rice oil is associated with increased abnormal sperm morphology and reduced sperm motility (Guo, et al. 2000), although effects on fertility resulting from prenatal exposure is still unknown.
Chlorinated furans, also called chlorinated dibenzofurans or CDFs, are toxic, persistent, bioaccumulative, and lipophilic ("fat-loving""). This means that CDFs build up and are stored in fatty tissues and fluid, such as breast milk, and can be passed on to fetuses and infants during pregnancy and lactation.
In humans, CDFs are associated with premature birth and abnormal development, liver toxicity, skin disease, eye inflammation, and damage to the nervous, immune, endocrine, and reproductive systems (ATSDR 1994b).
In laboratory animals, CDFs are known to cause a variety of effects including damage to the reproductive, endocrine, immune, and nervous systems. In addition, CDFs harm the kidneys and gastrointestinal tract, and cause birth defects (ATSDR 1994b).
2,3,7,8-TCDF (tetrafuran) has been found in 1 of the 34 people tested in EWG/Commonweal studies.
Top health concerns for 2,3,7,8-TCDF (tetrafuran) (References)
|health concern or target organ||weight of evidence|
|Immune system (including sensitization and allergies)||limited|
|Birth defects and developmental delays||unknown|
Results for 2,3,7,8-TCDF (tetrafuran)
in blood serum (lipid weight)
- found in 1 of 34 people in the group
|0||pg/g (lipid weight) in blood serum||0.22|
2,3,7,8-TCDF (tetrafuran) results
Detailed toxicity classifications (References)
|Limited evidence in humans - immune system toxicity||ATSDR (1998). Toxicological profile for chlorinated dibenzo-o-dioxins (CDDs): Health effects chapter. http://www.atsdr.cdc.gov/toxprofiles/tp104.html|
|Birth defects - weight of evidence unknown/unassessed||ATSDR (1998). Toxicological profile for chlorinated dibenzo-o-dioxins (CDDs): Health effects chapter. http://www.atsdr.cdc.gov/toxprofiles/tp104.html|