|Absorbing Titanium from Sunscreens|
Skin & Allergy News (February 1997, p. 15)Titanium dioxide, a compound whose toxicity remains unclear, is an ingredient found in many sunscreens. Researchers now say the chemical can be absorbed by human skin. Titanium dioxide is a fine, white powder, used in sunscreens because of its ability to reflect and scatter ultraviolet light. The compound’s full effects on human health are still under investigation. The U.S. government’s National Institute for Occupational Safety and Health (NIOSH) labels the chemical “a potential occupational carcinogen.”
|Sun-Care Chemical Proves Toxic in Lab Tests|
Mark Henderson, Science Correspondent
The Sunday Times (London)The main chemical used in sun lotions to filter out ultraviolet light may be TOXIC, particularly when exposed to sunshine.Octyl methoxycinnamate (OMC), which is present in 90 per cent of sunscreen brands, was found to kill mouse cells even at low doses in a study by Norwegian scientists.
It is not certain that the effects on mice are repeated in human beings, although the findings reported in New Scientist magazine suggest that human cells could be damaged if a sunscreen containing OMC penetrates the outer layer of dead skin and comes into contact with living tissue.
Terje Christensen, a biophysicist from the Norwegian Radiation Protection Authority, near Oslo, said her research showed that sunscreens should be treated with caution, and used only when it was impractical to stay indoors or to shield the skin from the sun with clothes.
The chemical is used as a filter for the more harmful UVB light. In Dr Christensen’s study, mouse tissue grown in culture was treated with a solution of OMC at five parts per million – a much lower concentration than in sunscreens. Half the cells treated with OMC died, compared with fewer than 10 per cent in a control experiment.
When researchers shone a lamp for two hours to simulate midday sunshine, more cells died. Dr Christensen suggested that the reaction between OMC and sunlight created an effect that was twice as toxic as the chemical alone.
The Cosmetic Toiletry and Perfumery Association, which represents sunscreen manufacturers in Britain, said that OMC “has been thoroughly tested for safety” and was approved by regulatory authorities in Europe and the US.
|Health concerns Place Sunscreen Ingredients Under Scrutiny|
Chemical Week, October 18, 2000 p24
The concern over OMC follows publication of a study last year which found that 2-phenylbenzimidazole-5-sulfonic acid (PBSA), a UV filter used in about 25% of sun lotions, may also damage human skin cells (Chemical Week, Jan 13, 1999, p.15). No studies show the effects from combining the two chemicals. BASF also manufactures PBSA.“
It is a theoretical possibility that human cells could be damaged by OMC,” says NRPA biophysicist Terje Christensen. NPRA researchers found that about 50% of cells died when exposed to a very low concentration of OMC. The toxic effect may also be magnified by exposure to sunlight, the researchers say. More cells died when light was shone on the cells in the OMC solution. “The problem is that some of the products formed when OMC is broken down by exposure to the sun are more toxic than the original substance,” says Christensen. OMC could harm human cells if it penetrates the outer layer of dead skin, he says.
Dr. Mercola’s Comment:
We ALL need sunshine to stay healthy. It is one of the essential ingredients for staying healthy. It is not the perniciously evil item that traditional medicine suggests that it is.
That does not mean that we should all go out and get sunburned. That should be avoided as it is likely to lead to an increase in skin cancer. However, prudent exposure to the sun, integrating the listening to your body concept, will not.
Adding sun screens is NOT a good way to limit your sun exposure. Staying out of the sun early on in the season and limiting your exposure until your system adjusts by increasing melanin pigmentation in your skin is.
Additionally, consuming many whole vegetables will increase antioxidant levels in the body which will also provide protection against any sun induced radiation damage.
So the bottom line is to avoid the sun screens. They are not necessary and will actually increase your risk of disease.
|Studies of Sunscreen Ingredients, 1998- Jane Sheppard-Publisher of Healthy Child|
Regarding the explosion of the sun and excess radiation, yesterday my daughter got a sunburn after I applied her normal amount of sunscreen that usually protects her. And it was foggy here most of the day. I wondered if there was excess radiation by the sun.I’m continuing to look for information on sunscreen ingredients. If anyone has more information, please e-mail me. I’m writing an article on this for the next issue of Healthy Child. The following are some of the studies I found:
Lancet 1997 Sep 20;350(9081):863-4
Some excerpts from this study:
“It is often assumed that little or none of a topically applied substance is absorbed into the systemic circulation. We show that substantial amounts of an applied sunscreen, oxybenzone, are absorbed and subsequently excreted in human urine. Oxybenzone has low acute
Oxybenzone is a benzophenone derivative commonly used throughout the world to make sun-products with especially high sun protection factors (SPF).”
“Our results suggest that sunscreens should not be the sole method of sun protection. It would be prudent not to apply oxybenzone to large surface areas of skin for extended and repeated periods of time, unless no alternative protection is available. There may be an
Other studies of interest:
2. Absorption of sunscreens across human skin: an evaluation of commercial products for children and adults
Aims Topical sunscreens are routinely applied to the skin by a large percentage of the population. This study assessed the extent of absorption of a number of common chemical sunscreen agents into and through human skin following application of commercially available products.
Methods Sunscreen products were applied to excised human epidermis in Franz diffusion cells with the amount penetrating into and across the epidermis assessed by h.p.l.c. for 8 h following application.
Results All sunscreen agents investigated penetrated into the skin (0.25 g m-2 or 14% of applied dose), but only benzophenone-3 passed through the skin in significant amounts (0.08 g m-2 or 10% of the applied dose). With one exception, sunscreen agents in corresponding products marketed for adults and children had similar skin penetration profiles.
Conclusions Whilst limited absorption across the skin was observed for the majority of the sunscreens tested, benzophenone-3 demonstrated sufficiently high penetration to warrant further investigation of its continued application.
3. Australas J Dermatol 1999 Feb;40(1):51-3
4. The PABA story.
The qualities of para-aminobenzoic acid (PABA) are discussed and an account is given of how it came to be the favorite sunscreen of the post World War II era. Slowly, however, dermatologists became aware that it was a fairly common sensitizer and that it tended to cross-sensitize with compounds of similar chemical structure both in contact with the skin and given as systemic drugs. Furthermore, continued exposure to chemicals of this type could lead to autoimmune responses especially systemic lupus erythematosus and dermatomyositis. Discussion of these complications from the use of PABA took place at two meetings of the Dermatological Association of Australia in 1964 and 1965, and played a part in the slow withdrawal of PABA from sunscreens.
Publication Types: Historical article
PMID: 10098293, UI: 99198366 29: FEBS Lett 1997 Nov 24;418(1-2):87-90
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5. Chemical oxidation and DNA damage catalyzed by inorganic sunscreen ingredients.
This is now a known carcinogen Titanium dioxide (TiO2) has been noted (US Federal Register, 43FR38206, 25 August 1978) to be an unsafe physical sunscreen because it reflects and scatters UVB and UVA in sunlight.
However, TiO2 absorbs about 70% of incident UV, and in aqueous environments this leads to the generation of hydroxyl radicals which can initiate oxidations. Using chemical methods, we show that all sunscreen TiO2 samples tested catalyze the photo-oxidation of a representative organic substrate (phenol). We also show that sunlight-illuminated TiO2 catalyses DNA damage both in vitro and in human cells. These results may be relevant to the overall effects of sunscreens.
PMID: 9414101, UI: 98074912
45: Toxicol Lett 1995 Oct;80(1-3):61-7
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6. Safety evaluation of benzophenone-3 after dermal administration in rats.
Benzophenone-3 (BZ-3) is a category 1 (over-the-counter) product approved by the US Food and Drug Administration (FDA) for use as a sunscreen agent in medicine, cosmetics, industry, and agriculture. This is due to its ability to absorb and dissipate ultraviolet light in a harmless manner, thus protecting human skin and products from UV irradiation. This study investigated the safety of BZ-3 after repeated administration. BZ-3 in ointment base was applied at a dose of 100 mg/kg body wt. twice daily, for 4 weeks to the skin of male Sprague-Dawley rats. Body weight, organ to body weight ratios, hematological, and clinical chemistry parameters were not effected. Pathological examination revealed no significant changes between control and treated animals. No gross external abnormalities were observed. Both in vivo and in vitro blood glutathione
(GSH) levels were effected by BZ-3 treatment. However, after 60 min of incubation, a reversal of this effect was observed in the treatment group as blood GSH levels approached normal levels. Furthermore, investigation of GSH-reductase and peroxidase with time indicated an increase in GSH-reductase activity at 60 and 90 min with no effect on GSH-peroxidase. Pre-treatment with phenobarbital modulated the metabolic disposition of BZ-3. There was an increase in the formation of the hydroxyl metabolites but not the O-dealkylated form. This study suggests that BZ-3 is not toxic to rats when applied dermally at a dose of 100 mg/kg body wt. for 4 weeks.
PMID: 7482593, UI: 96062138 65: FEBS Lett 1993 Jun 21;324(3):309-13
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7. Sunlight-induced mutagenicity of a common sunscreen ingredient.
We have tested the mutagenicity of a UV-B sunscreen ingredient called Padimate-O or octyl dimethyl PABA, which, chemically speaking, is identical to an industrial chemical that generates free radicals when illuminated. It is harmless in the dark but mutagenic in sunlight, attacking DNA directly. A commercial sunscreen containing Padimate-O behaves in the same way. UV-A in sunlight also excites Padimate-O, although less than UV-B. Some related compounds, including a known carcinogen, behave similarly. As mutagens may be carcinogenic, our results suggest that some sunscreens could, while preventing sunburn, contribute to sunlight-related cancers.
PMID: 8405372, UI: 94009604 64: J Toxicol Environ Health 1997 Aug 8;51(5):447-62
8. Effect of environmental conditions on the penetration of benzene through human skin.
Nakai JS, Chu I, Li-Muller A, Aucoin R
The in vitro penetration of [14C]benzene through freshly prepared human skin was examined under a variety of skin conditions associated with swimming and bathing. The experimental system utilized a recirculating donor solution and a flow-through receiver solution, and was modified to accommodate the analysis of volatiles. The permeability coefficient of 0.14 cm/h under standard conditions at 26 degrees C was found to increase to 0.26 cm/h at 50 degrees C and decrease to 0.10 cm/h at 15 degrees C. Storage of the skin at- 20 degrees C did not affect the penetration of benzene. Application of baby oil, moisturizer, or insect repellant to the skin before exposure under standard conditions did not affect the flux of benzene, but a significant increase was observed when the skin was pretreated with sunscreen (permeability coefficient 0.24 cm/h). These results suggest that risk assessment or exposure modeling for benzene and other environmental contaminants should account for appropriate changes in the environmental conditions when considering the dermal route of exposure.
PMID: 9233379, UI: 97377744
24: Mutat Res 1998 May 11;414(1-3):15-20
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9. Induction of sister chromatid exchanges and micronuclei by titanium dioxide in Chinese hamster ovary-K1 cells.
Titanium dioxide (TiO2) has color properties of extreme whiteness and brightness, is relatively inexpensive, and is extensively used as a white pigment in a variety of materials. TiO2, an effective blocker of ultraviolet light, is frequently added to sunscreens and cosmetic creams. However, the genotoxicity of TiO2 remains to be controversial. In this report, we have demonstrated that TiO2 can be transported into Chinese hamster ovary-K1 (CHO-K1) cells. The effects of TiO2 on induction of sister chromatid exchanges (SCE) and micronuclei (MN)
PMID: 9630482, UI: 98296327
9. Sunscreen Use Not Tied to Malignant Melanoma
|Skin Biology Aging Reversal SciencesTM|
Chapter 9.2 The Chemical Sunscreen Health Disaster
Questions about our products or need advice about what is best for you? Call Toll-Free 800-405-1912- Talk to Real People – No Phone Menus! Weekdays – Best Time – 10 am to 4 pm, Pacific Time or please send an email to Contact Skin BiologyFree Radical Generators and Gender-Bending Estrogenic Chemicals
Free Radical Generators and Gender-Bending Estrogenic Chemicals
On the other hand, over the past decade, many scientists studying cancer have come to virtually the opposite conclusion; that is, the use of sunscreen chemicals may be increasing the incidence of cancer and that sunlight exposure may actually decrease human cancer rates and improve your health.
It now appears that many heavily-used chemical sunscreens may actually increase cancers by virtue of their free radical generating properties. And more insidiously, many commonly used sunscreen chemicals have strong estrogenic actions that may cause serious problems in sexual development and adult sexual function, and may further increase cancer risks.
Despite the medical establishment’s near unanimity on the issue of sunlight exposure, on other health issues in the past, serious errors been promoted to the public.
1. In 1927, 12,745 physicians endorsed smoking Lucky Strike cigarettes as a healthful activity. In the 1940s and 1950s, thousands of prominent surgeons were used in national cigarette advertisements to reassure the public about the safety of cigarette smoking.
2. In the 1950’s, lobotomies were promoted for mental disorders and produced near-totally dysfunctional people.
3. In the 1960’s and 1970’s, diets high in omega-6 polyunsaturated fats and partially hydrogenated fatty acids such as safflower oil and margarine were recommended to reduce heart disease. However, long term studies found that, while such diets decreased heart disease, they increased the total death rate and the cancer rate and produced accelerated aging.
Chemical sunscreens have three primary defects:
1. They are powerful free radical generators.
2. They often have strong estrogenic activity.
3. They are synthetic chemicals that are alien to the human body and accumulate in body fat stores. The human body is well adapted to de-toxify biologicals that it has been exposed to over tens of millions of years. But it has often has difficulty removing new and non-biological compounds such DDT, Dioxin, PCBs, and chemical sunscreens.
Chemical sunscreens include:
Benzophenones (dixoybenzone, oxybenzone)
PABA and PABA esters (ethyl dihydroxy propyl PAB, glyceryl PABA, p-aminobenzoic acid, padimate-O or octyl dimethyl PABA)
Cinnamates (cinoxate, ethylhexyl p-methoxycinnamate, octocrylene, octyl methoxycinnamate)
Salicylates (ethylhexyl salicylate, homosalate, octyl salicylate)
Avobenzone [butyl-methyoxydibenzoylmethane; Parsol 1789] – This is the only chemical sunscreen currently allowed by the European Community. However, its safety is still questionable since it easily penetrates the skin and is a strong free radical generator.
|Sunscreen chemicals may generate free radicals within your body|
Most chemical sunscreens contain, as UVA and UVB blockers, from 2 to 5% of compounds such avobenzone, benzophenone, ethylhexyl p-methoxycinnimate, 2-ethylhexyl salicylate, homosalate, octyl methoxycinnamate, oxybenzone (benzophenone-3) as the active ingredients.Benzophenone (and similar compounds) is one of the most powerful free radical generators known. It is used in industrial processes as a free radical generator to initiate chemical reactions. Benzophenone is activated by ultraviolet light energy that breaks benzophenone’s double bond to produce two free radical sites. The free radicals then react with other molecules and produce damage to the fats, proteins, and DNA of the cells – the types of damage that produce skin aging and the development of cancer.
Adding to the problem is that large amounts of applied sunscreens can enter the bloodstream though your skin. In the 1970s, Prof. Howard Maibach warned that up to 35 percent of sunscreen applied to the skin can pass through the skin and enter the bloodstream but this had little effect on sunscreen promotion or safety testing. (Maibach, H. “NDELA-Percutaneous Penetration.” FDA Contract 223-75-2340, May 19, 1978) The longer sunscreen chemicals are left on the skin, the greater the absorption into the body. (Bronaugh, R.L., et al. “The effect of cosmetic vehicles on the penetration of N-nitrosodiethanolamine through excised human skin, J Invest Dermatol; 1981; 76(2): 94-96.) This may be a factor in the large increases in cancer (breast, uterine, colon, prostate) observed in regions, such as Northern Australia, where the use of sunscreen chemicals has been heavily promoted by medical groups and the local governments.
Many sunscreens also contain triethanolamine, a compound that can cause the formation of cancer causing nitrosamines in products by combining with nitrite used as preservative and often not disclosed on sunscreen labels.
In March 1998, Dr. John Knowland of the University of Oxford reported studies showing that certain sunscreens containing PABA and its derivatives can damage DNA, at least in the test tube experiments. When a chemical sunscreen, Padimate-O, was added to DNA and the mixture exposed to the ultraviolet rays of sunlight, it was found that the sunscreen broke down in sunlight, releasing highly active agents that could damage DNA. It did not block out the UV, but instead absorbed energy. “It became excited and set off a chemical reaction that resulted in the generation of the dangerous free radicals and broken DNA strands that can lead to cancer,” he said and further commented that while it’s too early to make blanket recommendations, “I would not use a product containing PABA, Padimate-O or other PABA derivatives.” Dr. Martin Rieger reported that PABA may play a role in DNA-dimer formation, a type of DNA damage that can induce carcinogenic changes.
Avobenzone (Parsol 1789) May Not Be Safe Either
However, avobenzone is a powerful free radical generator and also should have been banned. Avobenzone is easily absorbed through the epidermis and is still a chemical that absorbs ultraviolet radiation energy. Since it cannot destroy this energy, it has to convert the light energy into chemical energy, which is normally released as free radicals. While it blocks long-wave UVA, it does not effectively UVB or short-wave UVA radiation, and is usually combined with other sunscreen chemicals to produce a “broad-spectrum” product. In sunlight, avobenzone degrades and becomes ineffective within about 1 hour.
Do chemical sunscreens increase cancer?
Worldwide, the greatest rise in melanoma has been experienced in countries where chemical sunscreens have been heavily promoted The rise in melanoma has been exceptionally high in Queensland, Australia where the medical establishment has vigorously promoted the use of sunscreens. Queensland now has more incidences of melanoma per capita than any other place on Earth. (Garland, Cedric F., et al. Could sunscreens increase melanoma risk? American Journal of Public Health, Vol. 82, No. 4, April 1992, pp. 614-15).
Dr. Gordon Ainsleigh in California believes that the use of sunscreens causes more cancer deaths than it prevents. He estimates that the 17% increase in breast cancer observed between 1981 and 1992 may be the result of the pervasive use of sunscreens over the past decade (Ainsleigh, H. Gordon. Beneficial effects of sun exposure on cancer mortality. Preventive Medicine, Vol. 22, February 1993, pp. 132-40). Recent studies have also shown a higher rate of melanoma among men who regularly use sunscreens and a higher rate of basal cell carcinoma among women using sunscreens (Garland, Cedric F. et al. Effect of sunscreens on UV radiation-induced enhancement of melanoma growth in mice. Journal of the National Cancer Institute, Vol. 86, No. 10, May 18, 1994, pp. 798-801 :Larsen, H.R. “Sunscreens: do they cause skin cancer.” International Journal of Alternative & Complementary Medicine, 1994; 12(12): 17-19; Farmer K.C. & Naylor, M.F. “Sun exposure, sunscreens, and skin cancer prevention: a year-round concern.” Ann Pharmacother, 1996; 30(6):662-73)
Drs. Cedric and Frank Garland of the University of California have pointed out that while sunscreens do protect against sunburn, there is no scientific proof that they protect against melanoma or basal cell carcinoma in humans (Garland, C.F., et al. “Could sunscreens increase melanoma risk?” American Journal of Public Health, 1992; 82(4): 614-615.) The Garlands believe that the increased use of chemical sunscreens is the primary cause of the skin cancer epidemic. There is, however, some evidence that regular use of sunscreens helps prevent the formation of actinic keratoses, the precursors of squamous cell carcinoma (Dover, Jeffrey S. & Arndt, Kenneth A. Dermatology. Journal of the American Medical Association, Vol. 271, No. 21, June 1, 1994, pp. 1662-63).
In February 1998, epidemiologist Marianne Berwick of Memorial Sloan-Kettering Cancer Center in New York presented a careful analysis of data on sunscreen use and skin cancer at the annual meeting of the American Association for the Advancement of Science. Sunscreens may not protect against skin cancer, including melanoma, she concluded. “We don’t really know whether sunscreens prevent skin cancer,” said Berwick. She looked first at four studies of squamous cell cancer, a cancer that appears on the head, neck, and arms but is usually not lethal. Two of the studies concluded that sunscreen protected against a skin condition thought to precede squamous cell cancer while two other studies reported that sunscreen did not shield people from this type of skin cancer. She then analyzed two studies of basal cell carcinoma, another nonlethal skin cancer that is the most common form of skin cancer and appears most frequently on the head, neck, and arms. Those two studies found that people who used sunscreen were more likely to develop basal cell cancer than people who did not. She then analyzed 10 studies of melanoma, the skin cancer is the most deadly. Melanoma often starts in or near moles on the skin. In five of the melanoma studies, people who used sunscreen were more likely than nonusers to develop melanoma. In three of the studies, there was no association between sunscreen use and melanoma. In the final two studies, people who used sunscreen seemed to be protected. (Source: Science News, Vol. 153, No. 23, June 6, 1998, p. 360).
“After examining the available epidemiological data and conducting our own large case-control population-based study, we have found no relationship between sunscreen use at any age and the development of melanoma skin cancer,” said Dr. Berwick. Although sunscreens do prevent sunburn, Dr. Berwick concluded that sunburn itself is not the direct cause of cancer. Dr. Berwick objected to the universal blanket advice about using sunscreens during all time spent outdoors.
Dr. Berwick previously conducted a 1996 study that found no link between sunscreen use at any age and the development of melanoma. The same study also found no relationship between a history of sunburn and the development of melanoma. Berwick continued saying that the relationship between sunscreen use and the development of skin cancer is complicated by evidence that people who are sensitive to the sun engage in fewer activities in the bright sun and wear sunscreen when they do. But if these people develop melanoma, it may be because they are genetically susceptible and likely to develop skin cancer regardless of the amount of sunlight exposure or protection from sunscreen.
“Based on the evidence, we conclude that sunburn itself probably does not cause melanoma, but that it is an important sign of excessive sun exposure particularly among those who are genetically susceptible because of their skin-type,” said Dr. Berwick. The melanoma risk for people with numerous moles was six times higher than that of someone with only a few moles. Persons most at risk for melanoma are those with red or blond hair and lighter colored eyes. Such light-skinned people have almost six times more melanoma than persons with darker skin. “The evidence indicates that chronic sun exposure may be protective for the development of melanoma because the skin has adapted to the sun, having become thicker as it has tanned. On the other hand, intermittent sun exposure appears to increase risk, making it much less protective,” added Dr. Berwick. “People need to focus on their individual risk characteristics, such as their pigmentary phenotype, their family history, and the type and number of moles they have. I recommend that people avoid the sun when they are clearly at high risk and that they should enjoy a reasonable amount of outdoor activities with less anxiety when they are clearly at reduced risk,” advised Dr. Berwick.
After Dr. Berwick’s presentation of this data, the American Academy of Dermatology (ADA) issued a press release attacking her work. The then president of the ADA insulted her as a “number crunching scientist”. But then, all scientists spend a lot of time crunching numbers.
Studies have found that the incidence of skin cancers has increased even as sunscreens have become popular among fair-skinned people. The establishment answer to this increase in the cancer rate is that wearing sunscreen makes people stay in the sun too long. A study by Drs. Mike Brown (Kate Law of the Cancer Research Campaign) Philippe Autier (European Institute of Oncology in Milan) reported that children using sunscreen returned from holiday with more skin moles – a possible sign of increased cancer risk. Some say that people who wore higher factor sunscreens tend to stay out in sunlight much longer, because they fell protected. However, others have pointed out that if sunscreen chemicals were protective, the factors of longer sun exposure would be somewhat countered by the sunscreen’s supposed protective actions.
|Skin cancer increase not due to ozone depletion|
But what about ozone depletion and skin cancer? Could this be the cause of the increased skin cancer rates? Professor Johan Moan of the Norwegian Cancer Institute found that the yearly incidence of melanoma in Norway had increased by 350% for men and by 440% for women during the period 1957 to 1984. He also determined that there had been no change in the ozone layer over this period of time. He concludes his report in the British Journal of Cancer by stating “Ozone depletion is not the cause of the increase in skin cancers” (Moan, J. & Dahlback, A. The relationship between skin cancers, solar radiation and ozone depletion. British Journal of Cancer, Vol. 65, No. 6, June 1992, pp. 916-21).
|Psoriasis Treatment Increases Skin Cancer 83-fold |
Researchers at the Harvard Medical School discovered that psoralen, another ultraviolet light-activated, free radical generator that is chemically similar to sunscreens, is an extremely efficient carcinogen. They found that the rate of squamous cell carcinoma among patients with psoriasis, who had been repeatedly treated with UVA light after a topical application of psoralen, was 83 times higher than among the general population (Stern, Robert S. and Laid, Nan. The carcinogenic risk of treatments for severe psoriasis. Cancer, Vol. 73, No. 11, June 1, 1994, pp. 2759-64).
Toxic Estrogenic Chemical Sunscreens
Even worse for your health is the fact that many common free radical generating sunscreen chemicals also have estrogen like-effects. Such effects can increase cancers, cause birth defects in children, lower sperm counts and penis size in men, plus a plethora of other medical problems. These effects are similar to many banned chemicals such as DDT, Dioxin, PCBs.
Some of these effects may be more subtle than physical abnormalities and may manifest themselves as behavioral changes (Fox et al. 1978), such as aberrant behavior of birds during nesting, which can have significant effects on their nesting success.
Government regulations require that new chemicals pass screening tests to determine that they do not cause cancer. But no rules yet require similar testing of chemicals for effects on reproductive hormones.
Common Estrogenic Toxins
Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin and similar chemicals)
PCBs (Polychlorinated Biphenyls)
Expected Effects of Estrogenic Chemicals in Humans
Lowered Sperm Counts
Discovery of Gender-Bending Estrogenic Chemicals in the Environment
In the 1950s, the effect of estrogenic toxins such as DDT was linked to eggshell thinning in many bird species. Chemicals with estrogen-like actions can also cause severe developmental problems such as turning fish into hermaphrodites. Over the past 50 years, studies on estrogenic toxins have greatly expanded our knowledge of these effect – some of which is detailed below.
Many hormone affecting chemicals remain in widespread use. 2,4-D, and similar products, are largest-selling broadleaf herbicides in North America and some 60 million pounds of such chemicals are applied annually in the USA alone. Three widely used pesticides are estrogenic: dieldrin, toxaphene, and endosulfan. While dieldrin and toxaphene have been banned, endosulfan remains the USA’s most heavily used pesticide.
Not all environmental gender-benders are estrogenic. Benomyl, a fungicide used on crops such as rice, tomatoes, apples, and grapes, has toxic actions on the testes where it causes the premature release of cells that would have become sperm.
Also, the greatest increases in human cancers over the last 30 years have been those of the breast, ovaries, testes, and prostate, all tissues that are sensitive to sex hormones.
Margaret Schlumpf and her colleagues (Institute of Pharmacology and Toxicology, University of Zurich, Switzerland) have found that many widely-used sunscreen chemicals mimic the effects of estrogen and trigger developmental abnormalities in rats. (Schlumpf , Margaret; Beata Cotton, Marianne Conscience, Vreni Haller, Beate Steinmann, Walter Lichtensteiger. In vitro and in vivo estrogenicity of UV screens. Environmental Health Perspectives Vol. 109 (March 2001) pp 239-244)
Her group tested six common chemicals that are used in sunscreens, lipsticks and facial cosmetics. Five of the six tested chemicals (benzophenone-3, homosalate, 4-methyl-benzylidene camphor (4-MBC), octyl-methoxycinnamate and octyl-dimethyl-PABA) behaved like strong estrogen in lab tests and caused cancer cells to grow more rapidly.
Schlumpf’s group also found estrogenic sunscreens in the breast milk of mothers at levels of nanograms per kilogram of fat. This is the about same level as other known environmental contaminants such as PCBs. Schlumpf commented that this exposure could be dramatically increased in childhood by the large amount of sunscreen used by bathers, especially children. Her group is following the offspring of 4-MBC exposed rats to see if they develop health problems.
Based on these results, the Swiss researchers concluded that the impact of sunscreens containing these “endocrine disruptors” should be investigated more closely, in particular their penetration through human skin.
Estrogenic Synergies May Multiply Toxic Effects
Combinations of estrogenic sunscreens and other pollutants may act together to intensify their effects. Researchers at Tulane University in New Orleans believe that a mixture of estrogenic toxins — such as sunscreens, PCBs, DDT, etc., are more harmful if mixed together. The Tulane researchers found one mixture of estrogenic toxins to be 160 to 1600 times more toxic than the individual chemicals in the mixture.
Gender-Bending Effects are Most Severe During Early Development
Current evidence points to early development (embryo, fetus, juvenile) as the time when children’s organs are the most sensitive to estrogen exposure and developmental abnormalities. However, some effects may not become apparent until later in life, when normal sexual maturity is expected.
The basic human form is female. Early in fetal development, the genes must signal if a fetus is to be male. The secretion of male hormones is the signal that activates genes that cause male development. If this does not happen, the human has female imprinting – regardless of whether the person’s cells have male (XY) or female genes (XX). If a mother has been exposed to a natural estrogen or estrogenic toxin during the crucial period when genes normally activate masculine patterns, the seventh and 14th weeks of pregnancy, then there is not the proper switching from female to male. If the estrogenic toxins only appear sporadically (such as when the mother uses an estrogenic sunscreen, the disruptions may not trigger a complete reversal of a male’s gender, but may exert subtle physical (such a reduced penis size) and mental changes (such as sex role confusion) that become apparent later in life. Conversely, if a synthetic compound blocks estrogen actions, this can produce the sex organs of a male in a fetus that is genetically female.
After using chemical sunscreens, a pregnant woman mother may unwittingly pass some hormone-mimicking pollutants to her child before birth through her placental blood supply and via her breast milk with which she later feeds her newborn.
Some currently used pesticides have been found to interfere with male development, producing undescended testes, nipples on males, hypospadias, decreased sperm counts, and altered mating behavior. When a widely used insecticide, methoxychlor, was fed at low doses to pregnant mice, it caused permanent increases in prostate weight in male offspring of females.
Endocrine disruptors can affect male/female sex ratio in Daphnia (a water flea).
Feminized Male Alligators
Male alligators exposed to pesticides in Florida have difficulty reproducing, partly because their penises are not developing to normal size. Effects attributed to estrogenic environmental toxins have produced male American alligators with underdeveloped sex organs and vitellogenin (an egg and yolk protein normally found only in females) in male animals.
In addition, males of of many other wildlife species in the same areas of Florida (birds, fish, amphibians, and mammals) are being “feminized” by exposure to low levels of pesticides and other toxic chemicals released into the environment.
The Florida panther, an endangered species, is failing to reproduce itself. There are only 30 to 50 panthers remaining, and the reason for the decline has postulated to an effect of environmental estrogens. Between 1985 and 1990, 67 percent of male panthers were born with one or more undescended testicles (cryptorchidism). Some Florida panthers are sterile and many others produce abnormal or deformed sperm.
Loss of Libido in Men
Many industrialized countries have witnessed recently a sharp rise in testicular cancer, according to Dr. Skakkebaek, (Department of Growth and Reproduction at Rigshospitalet, Copenhagen, Denmark). Some of the first data reporting this increase emerged in Denmark, which has maintained a national cancer registry since 1947.
In Denmark, the incidence of testicular cancer has more than tripled over the past 50 years and the rate of increase continues to grow. Similar increases have also been reported in Scotland, the United States, and other Scandinavian countries.
Human Sperm Counts Decline
The sperm count in men in industrialized countries has dropped 50% during the past 50 years, and the exposure to endocrine-disrupting compounds is the most likely cause. Skakoebaek and his group conducted an analysis of previously published studies on semen quality. The international data, from studies involving 14,947 men, indicate that the average density of sperm has fallen from 113 million per milliliter of semen in 1940 to just 66 million per ml in 1990.
Skakkebaek’s group also noted that because the volume of semen available in these men at any given time has also dropped an average of 19 percent, the 50-year drop in sperm count has been larger than sperm density alone would indicate.
Undescended Testicles (cryptorchidism)
Only a few countries maintain registries on this condition, but Skakkebaek found that two British studies documented a near doubling of the number of boys born with at least one undescended testicle from about 1.6 percent in the 1950s to 2.9 percent in the late 1970s.
Other studies have reported that in England and the USA, cryptorchidism has more than doubled in men during the last four decades. (A. Giwercman and N.E. Skakkebaek, “The human testis–an organ at risk?” INTERNATIONAL JOURNAL OF ANDROLOGY Vol. 15 (1992), pgs. 373-375: Elisabeth Carlsen and others, “Evidence for decreasing quality of semen during past 50 years,” BRITISH MEDICAL JOURNAL Vol. 305 (1992), pgs. 609-613)
In young boys living in an area of heavy agricultural activity on the Spanish Mediterranean coast, there was found an association between pesticide exposure and undescended testicles.
Hypospadias in Men
All these changes may be the consequence of fetal exposure. Testicular cancer, undescended testicles, hypospadias, and poor-quality semen have been found in the male offspring of women who, during pregnancy, were treated with diethylstilbestrol (DES), a potent synthetic estrogen. Research at the National Institute of Environmental Health Sciences in Research Triangle Park, N.C. found many environmental contaminants can mimic the reproductive effects of estrogen and DES in male animals.
Estrogenic PCBs and Insecticides Diminish Penis Size in Humans and Animals
Boys in Taiwan exposed to PCBs (polychlorinated biphenyls) while in their mothers’ womb developed smaller than normal penises as they matured.
“PCB Exposure Linked to Birth Defects in Taiwan,” NEW YORK TIMES August 2, 1988, pg. C3)
The boys in Taiwan are called the “yucheng” (or “oil disease”) children. A similar PCB contamination (“yusho”) occurred in Japan in 1968. When 115 yucheng children were examined, they were found to be delayed when compared to controls. The delayed development effects in the children’s behavior that were most noticeable were the age when they first (1) talked with sentences, (2) turned pages of books, (3) carried out requests of parents, and (4) were able to hold pencils and catch balls.
The boy’s mothers had eaten PCB-contaminated rice oil in 1979. The children consumed none of the oil but they were exposed before birth to PCBs in their mother’s blood and after birth to PCBs in their mother’s milk. The rice oil contained 100 parts per million (ppm) PCBs. A new mother in the USA has an average of one ppm PCBs in her breast milk.
Researchers at University of Wisconsin found low exposures before birth to dioxin, another toxic estrogen, feminized the behavior of male rats during adulthood, and sharply reduced their sperm production. The researchers concluded that the fetal male reproductive system was more sensitive to dioxin than any other organ-system studied.” (Janet Raloff, “The Gender Benders,” SCIENCE NEWS Vol. 145 (January 8, 1994), pgs. 24-27; Perinatal dioxin feminizes male rats,” SCIENCE NEWS Vol. 141 (May 30, 1992), pg. 359; “EcoCancers,” SCIENCE NEWS Vol. 144 (July 3, 1993), pgs. 10-13)
Santa Barbara’s Lesbian Seagulls
Dr. Michael Fry at University of California, Davis, reported that Western gulls on Santa Barbara Island are often in recent years becoming lesbian gulls, with female pairs building nests and trying to hatch eggs and raise offspring. Fry attributes this as partly due to male seagulls’ increasing indifference to sex. Examinations found that the male gulls often have feminized sex organs, attributed to the males being “chemically castrated” by DDT and other estrogenic other environmental pollutants.
Symptoms of excessive estrogen in women
In women, excessive estrogen and estrogen-like chemicals produce intensified estrogen effects on the body.
1. Affects your fluid balance, so that swelling due to fluid retention may become noticeable. It can causes elevations of blood pressure, headaches, and migraines.
2. Has a stimulating effect on breast tissue but excess estrogen can also increase fibrocystic breast disease and painful breast swelling.
3. Suppresses thyroid hormone production and this may cause fatigue plus aches and pains in muscles and joints.
4. Stimulates the appetite, makes you crave sweets, leads to weight gain from fat as well as fluid.
5. Intensifies PMS symptoms and produce a mental feeling of being edgy and nervous. Insomnia is also a common side effect.
6. Increases your chances of developing emdometriosis, breast cancer, and uterine cancer.
The Failure of Academic Dermatologists to Protect the Public
Why did this situation with sunscreens arise? Why was it only research scientists who repeatedly raised concerns about sunscreen safety? Why was the academic dermatology community silent?
Pauling eventually won the 1962 Nobel Peace Prize for his campaign and nuclear weapons testing in the atmosphere was terminated. But even today, in year 2002, a study by the Center for Disease Control estimated that the radioactive fallout from the atmospheric nuclear weapons tests caused about 11,000 deaths from cancer in the USA and produced a minimum of 22,000 new cancers. Some non-governmental groups are of the opinion that the deaths were far higher and still are responsible for 15,000 deaths yearly in the USA.
Many other academics have, in recent years, led protests against actions and policies that were damaging to the wider community. These include campaigns to remove chemical toxins from foods, clothes, building materials and the wider environment. Other concerns over global warming, species extinction, and global poverty have been sharply delineated by members of the academic community.
This raises the questions as to why no member of the academic dermatology community, over the past 30 years, raised warnings about the dangers of chemical sunscreens. The answer is that the cosmetic industry has effectively silenced leading academic dermatologists by a widespread pattern of payments in the form of consulting fees, grants, retainers, vacation arrangements, and so on. In essence, industry has bought their silence on issues and products that might be embarrassing. Most academic dermatologists focus their attention on innocuous, safe, non-controversial topics that will not offend their corporate sponsors. Like Dr. Faust, they must honor their agreements with their benefactors.
Wider Social Effects of Estrogenic Sunscreens