Glowing fish

Glowing fish

29 April, 2013
Pollutant indicator
Hong Kong company uses fish embryos to detect endocrine disruptors

The scary thing about many environmental hazards is they’re invisible to the naked eye. That makes them difficult to avoid. 
But scientists in a small, aquarium-filled lab at the Hong Kong Science and Technology Park in Shatin are bringing some of the worst unseen dangers in our everyday environment to light, literally.
They do this by using teeny, tiny fish embryos that have been engineered with an artificial gene that produces a glowing fluorescent protein that lights up in varying intensities of green when it comes in contact with estrogen endocrine disruptors (EEDs), environmental pollutants that can mess with reproductive systems and cause reproductive-related cancers. The more estrogenic the material, the brighter green the embryos get.
Vitargent (International) Biotechnology Ltd. would like to use its magical fish to find toxins in the waters in and around Hong Kong. Late in March, the Environmental Protection Department gave the first sign it may use the company’s technology as a biological indicator for the government’s biological monitoring program, according to an email from the EPD sent to Vitargent.
Vitargent has been asking the government to consider using its technology for routine water quality monitoring, but the EPD still isn’t prepared to do that, according to the email.
The EPD says about 80 physio-chemical, biological, and microbiological parameters currently are analyzed from marine water samples at 76 stations. A similar set of parameters is analyzed in sediment samples at 60 stations.
The Hazardous Chemicals Control Ordinance, meanwhile, regulates through a permit system, the import, export, manufacture and use of non-pesticide hazardous chemicals that have potentially harmful or adverse effects on human health or the environment, including those regulated by the Stockholm Convention and the Rotterdam Convention, an EPD spokesperson said in an email.
The treatment and disposal of chemical waste in Hong Kong is subject to cradle to grave control under the Waste Disposal Ordinance, according to the EPD.
Persistent organic pollutants (POPs) like dioxins, polychlorinated biphenyl (PCBs), dichlorodiphenyltrichloroethane (DDT), and other pesticides, are also monitored under the toxic substances monitoring program the EPD spokesperson said.
To monitor for toxic substances now, the government uses a type of chemical analysis technology called gas chromatography-mass spectrometry, the EPD said.
But that’s not enough, according to Eric Chen, director of Vitargent.
More than 87,000 chemicals are used in the commercial world, according to the World Health Organization and the United Nations, Chen says, arguing the EPD’s testing method can only detect about 100 of them. The reason is chemical analysis is “very target specific and cannot reflect the real biological effect on a living organism,” he says.
Officials at the Environmental Protection Agency in the U.S. and the OECD have started to do biological testing to get a more precise result, Chen says.
That approach has kick-started Vitargent’s business, which relies on fish embryos – a biological source – to find endocrine disruptors. The embryos can detect the presence of any endocrine-disrupting substance, no matter what the source, making the hunt for one of thousands of specific chemicals unnecessary, Chen says.
The company, which got off the ground in 2010 with HK$10 million in funding from the Hong Kong Innovation Technology Commission, a government organization, as well as a “few million” more from angel investors, is doing a brisk business with cosmetic and personal care product companies in Europe and the U.S., according to Chen.  
That’s because European and U.S. governments are requiring companies to comply with rules and regulations –such as the European Commission’s Registration, Evaluation, Authorization and Restriction of Chemical (REACH) legislation—that seek to prevent the flow of EEDs into the environment.
Revenue at Vitargent, rose by five times last year as a result of interest from personal care and cosmetics companies overseas, Chen says. Vitargent expects to seek more funding so it can speed up commercialization of its luminescent embryos, which are derived from the Asian medaka fish. There are “lots of potential clients,” Chen says.
Vitargent is not alone in developing space-age technology to track down nasty pollutants. A French company called WatchFrog has created “fluorescing” tadpoles to detect chemicals that disrupt normal thyroid functions, according to an article last month in ScientificAmerican.
As for endocrine disruptors, these chemicals can be found in a wide range of products, from shampoos and hand creams and cosmetics, to chicken and milk powder. They can harm people who consume them, and, because cosmetics, personal care products, and food end up back in the environment through waste and water systems, they can harm others as well. Endocrine disruptors also can harm fish and wildlife that come in contact with them.
Hundreds of endocrine disruptors are known, and include many of the unpronounceable chemicals listed in small print on the back of sun tan lotions and cosmetics, like 3-Benzyliden Camphor, Benzophenone 1 & 2, Butyl paraben and Diethyl phthalate, to name a few.
But any one of thousands of chemicals, or combinations of chemicals, known and unknown, can interfere with the endocrine system. Testing for these chemicals in nature can be hit or miss – there are so many potential endocrine disruptors, that finding the right chemical or combination of chemicals is nearly impossible, Chen says. 
The Hong Kong EPD says that, according to a number of studies, chemically enhanced primary treatment and biological treatment is effective at removing many types of endocrine disruptors in sewage that get there from household product use.
“Since the sewerage network of Hong Kong covers some 93 percent of the local population, the levels of EDCs (endocrine disruptors) in local marine waters are generally very low, the EPD spokesperson said.
“Indeed, based on our monitoring results since 2004, the levels of POPs in our marine waters are either below detection limits or very low, and they are below relevant overseas standards for the protection of aquatic life and do not pose (a) risk to the marine ecosystem,” the spokesperson continued.
Since coastal waters have low levels of endocrine disruptors, the health risk due to exposure to EDCs at bathing beaches is low, the EPD said.
Chen has said that conclusion is “irresponsible” and says projects Vitargent has undertaken with TVB Pearl and with the EPD have shown some areas, such as in Tsim Sha Tsui, have excessive endocrine disruptors. Nonetheless, Chen is encouraged the EPD recently asked Vitargent to submit a proposal to do biological monitoring.
Because Vitargent considers identifying endocrine disruptors in the environment to be part of its “social mission,” the company is also working on partnering with non-governmental organizations focused on protecting nature, or those that work with cancer patients affected by endocrine disruptors.
The EPD spokesperson, meanwhile, said the government will keep abreast of the latest scientific developments and local research study findings in its monitoring work.

By: Abby Schultz


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