2007年04月02日 蘋果日報
暖化毀珊瑚礁 毒藻成殺手
年有五萬人吃魚中雪茄毒 專家：影響地區正增加【蔡佳慧╱綜合外電報導】聯合國科學家與124國代表今起在比利時召開會議，預定周五將提出「全球暖化」最終報告，做為各國制定政策與相關立法的依據。在此同時，美國海洋學家警告，全球暖化除了造成陸地動植物滅絕，冰河冰山快速融解之外，也正在提高人類食用海洋魚類中毒的機率。
根據美聯社報導，菲律賓近年來頻傳集體食物中毒案例，中毒者出現嘔吐、身體疼痛、麻痺等徵狀，甚至無法開口說話。檢驗發現，他們身中的是神經毒素「雪茄毒」(ciguatera)，來源則是他們在毒發數小時前所食用的梭魚等魚類。21歲學生盧亞中毒時，不僅頭部麻木、手部刺痛，甚至連呼吸都有困難。他說：「我嚇呆了，當時還以為自己死定了」。
有毒海藻種類增加
「雪茄毒」來自有毒海藻，透過小魚、大魚等食物鏈累積，最終被人類吃下腹，引發人類中毒。根據估計，目前全球每年約有五萬人雪茄毒中毒，其中大約九成都未通報。針對特定魚隻是否含有雪茄毒，目前尚無可靠的測試方式。目前也沒有雪茄毒的解毒劑，醫師只能施打點滴和利尿劑來舒緩病患的痛苦。
然而專家指稱，目前全球暖化問題日趨嚴重，加上人類不斷污染海洋，已導致珊瑚礁大量受到破壞，有毒海藻藉機大量增生，因此未來雪茄毒中毒的機率也持續高漲。
美國麻州海洋學家安德森(Donald M. Anderson)說：「就全球而論，目前海鮮類食物因海藻毒素所引發的問題，比20、30年前高出甚多。不光是毒素增加，有毒海藻種類增加，全球受影響的區域也在增加之列。」
最終報告周五出爐
事實上，聯合國氣候變遷跨政府小組(Intergovernmental Panel on Climate Change，簡稱IPCC)今起召集各國代表和科學家，針對暖化危機將如何影響全球，以及人類應該採取何種避免措施的報告討論修改。周五最終報告即將出爐，而根據美聯社提早取得的內容顯示，科學家預測，全球暖化將嚴重破壞海洋生態系統，而海洋也因二氧化碳而酸化，威脅珊瑚礁、浮游生物和經濟魚類等生物。
科學家甚至形容，這份預測報告指出了「通往滅絕的高速公路」，不過，哈佛大學海洋生物學教授麥卡錫(James McCarthy)樂觀地說：「最糟狀況將不會發生，我們不至於那麼愚蠢。」
全球暖化導致人類染上雪茄毒過程
1.人類將大量二氧化碳排放在空氣中，造成全球暖化。
2.全球暖化導致海水溫度上升，外加海水中的二氧化碳含量提高，促使珊瑚大量死亡，有毒海藻則藉機增生。
3.小魚吃下有毒海藻之後，雪茄毒素進入小魚的肌肉組織及內臟。
4.梭魚等其他大魚吃下小魚之後，體內累積雪茄毒素。
5.人類食用大魚後雪茄毒中毒 ，出現包括口手麻痺、無法言語、嘔吐等症狀。
資料來源：綜合外電
報你知
雪茄毒尚無藥可解
「雪茄毒」（ciguatera）是一種神經毒素，來自有毒海藻，小魚在吃下海藻後，會把毒素累積在體內，大魚吃小魚後，又把毒素累積在大魚體內。最後人類食用大魚而中毒，會出現嘔吐、身體疼痛、麻痺等徵狀，甚至呼吸困難、無法言語。
目前雪茄毒無解毒劑，只能藉施打點滴和利尿劑舒緩病患痛苦，靠病患自行復元。
Odd Global Warming Threat: Toxic SeafoodBy Michael Casey, Associated Press
02 April 2007
ILOILO, Philippines (AP) -- Bowls of piping hot barracuda soup were the much-anticipated treat when the Roa family gathered for a casual and relaxing Sunday meal.
Within hours, all six fell deathly ill. So did two dozen others from the same neighborhood. Some complained of body-wide numbness. Others had weakness in their legs. Several couldn't speak or even open their mouths.
"I was scared. I really thought I was going to die,'' said Dabby Roa, 21, a student who suffered numbness in his head, tingling in his hands and had trouble breathing.
What Roa and the others suffered that night last August was ciguatera poisoning, a rarely fatal but growing menace from eating exotic fish. All had bought portions of the same barracuda from a local vendor.
Experts estimate that up to 50,000 people worldwide suffer ciguatera poisoning each year, with more than 90 percent of cases unreported. Scientists say the risks are getting worse, because of damage that pollution and global warming are inflicting on the coral reefs where many fish species feed.
Dozens of popular fish types, including grouper and barracuda, live near reefs. They accumulate the toxic chemical in their bodies from eating smaller fish that graze on the poisonous algae. When oceans are warmed by the greenhouse effect and fouled by toxic runoff, coral reefs are damaged and poison algae thrives, scientists say.
"Worldwide, we have a much bigger problem with toxins from algae in seafood than we had 20 or 30 years ago,'' said Donald M. Anderson, director of the Coastal Ocean Institute at the Woods Hole Oceanographic Institution in Massachusetts.
"We have more toxins, more species of algae producing the toxins and more areas affected around the world,'' he said.
Although risk of ciguatera has soared recently, the phenomenon is ancient. Fish poisoning shows up in Homer's Odyssey. Alexander the Great forbade his armies to eat fish for fear of being stricken, according to University of Hawaii professor Yoshitsugi Hokama.
Capt. James Cook and his crew probably suffered ciguatera poisoning in 1774 after eating fish near Vanuatu in the South Pacific, according to crew journals and correspondence studied by Dr. Michael Doherty of the Swedish Epilepsy Center in Seattle, writing in the scientific review Neurology. Cook recorded that they "were seized with an extraordinary weakness in all our limbs attended with a numbness or sensation like ... that ... caused by exposing one's hands or feet to a fire after having been pinched much by frost.''
Ciguatera has long been known in the South Pacific, the Caribbean and warmer areas of the Indian Ocean. Some South Pacific islanders use dogs to test fish before they eat.
But in the past decade, it has spread through Asia, Europe and the United States, where more restaurants are serving reef fish, prized for their fresh taste and exotic cachet.
In the United States, ciguatera poisonings are most frequent in Florida, Texas and Hawaii, which has seen a fivefold increase since the 1970s to more than 250 a year.
Hong Kong, which imports much of its seafood, went from fewer than 10 cases annually in the 1980s to a few hundred now.
Still, Hong Kong diners pay a premium for the risky fish. Rare species like the Napoleon wrasse fetch nearly $50 a pound. The fish are increasingly shipped live from Southeast Asia and as far away as the South Pacific, raising concerns from the World Conservation Union that many species, especially groupers, could be fished out of existence.
Professor Yvonne Sadovy, of the University of Hong Kong, predicted that high demand and cash-hungry fishermen mean that "ciguatoxic fish entering markets around the world is going to increase.''
Should global warming and pollution worsen and boost ciguatera poisonings, as most experts predict, health officials will face a daunting challenge.
Currently, there is no reliable way to detect whether a fish has ciguatera. The molecule is extremely complex and differs markedly from region to region.
There also is no antidote.
Furthermore, doctors are often ill-equipped to diagnose ciguatera, which has a range of symptoms and is sometimes misdiagnosed as chronic fatigue syndrome or other maladies.
Those challenges faced Dr. Edgar Portigo at Doctors General Hospital in Iloilo, about 265 miles southeast of Manila, when the Roa family and others arrived. The emergency room was filling with patients yelping in pain, vomiting, or, in the case of Dabby Roa, so paralyzed that he had to be carried in by a security guard.
"Normally, you have one or two emergency cases. Here we had 30 plus all at once,'' from ages 4 to 65, Portigo said.
At first, Portigo surmised the patients had heavy metal poisoning. But when he learned of the common thread -- the barracuda dinners -- he sent a sample of the fish to Manila for testing. It came back positive for ciguatera.
Portigo gave his patients intravenous drips and a diuretic to relieve their suffering. Most like Roa were released from the hospital in a week, he said, and fully recovered.
"Although this is quite rare, it can happen anytime,'' said Portigo, noting this was the first ciguatera outbreak in the city.
A relatively quick recovery is the norm, but some have lingering symptoms.
Dennis McGillicuddy, a 65-year-old retired cable television company owner from Sarasota, Fla., fell sick a few hours after eating a mutton snapper he caught off the coast of Bermuda in 2000. Within hours, his vomiting and diarrhea were so severe that he became delirious and was "reduced to crawling,'' he recalled.
The digestive symptoms lasted two weeks. After that, McGillicuddy became so sensitive to temperature extremes that it was hard to take a shower. Numbness in his extremities lasted for almost a year.
"I've never had anything like this,'' said McGillicuddy, who still occasionally feels tingling in his left arm. "You feel terrible all over your body.''
The U.S. Food and Drug Administration and others who monitor ciguatera say they are hampered by the lack of a reliable test. Bans on certain fish or "hot spots'' can help, but they often are impractical.
"It's very hard to manage,'' said professor Richard Lewis, of the University of Queensland in Australia, who has studied ciguatera. "Unless you don't eat the fish, you have a risk of getting ciguatera.''
Poorer countries often lack even rudimentary measures to protect consumers. Those precautions that do exist are undermined by government corruption or lack of enforcement.
Hong Kong has refused to enact mandatory measures to prevent ciguatera despite increased outbreaks. It argues that educating consumers and traders is the answer, rejecting calls to crack down on traders or ban fish from suspect areas.
"Given the fact we eat so much seafood in Hong Kong, this should be one of the priorities in protecting the population,'' Sadovy said. "I just hope we don't have to wait for someone to die before something is done.''
In Iloilo, fear has done what the Philippine government has not. Consumers stopped buying barracuda after the ciguatera outbreak. Vendors have switched to less risky varieties.
2007年04月02日 蘋果日報
全球暖化 恐爆糧荒掀戰爭
專家警告
全球暖化不但影響天候，威脅人身財產安全，聯合國氣候變遷跨政府小組（Intergovernmental Panel on Climate Change，簡稱IPCC）最新報告甚至指出，全球60餘國正因為暖化造成的食物短缺、飲水不足面臨戰爭威脅，還警告包括中國、美國及部分歐洲國家也將因為氣候變遷陷入爭奪資源的衝突。
IPCC報告召集2500名科學家耗時6年完成，2月初第1份報告指出，過去半世紀氣溫升高「很可能」是人類燃燒石油造成，全球暖化有「9成」是人類種下的禍根。即將在周五公布的第2份報告稱，暖化影響證據在世界各地清楚可見。
未來20年拉美缺水
報告指未來20年間，中南美數千萬及非洲數億人民將飽受缺水之苦，到了2050年，10億亞洲人恐面臨缺水威脅。2035年，灌注亞洲各大河川的喜馬拉雅山冰河可能融化殆盡，影響7億人口生計。
雖然暖化延長植物生長季，暫時增加穀物收成，但2050年代到來之際，印度糧產可能減少3成，使1.3億人口瀕臨饑荒。
2080年，海平面上升將淹沒許多城市，每年造成1億人無家可歸。但人類真的對這許多危機束手無策？IPCC 5月的第3份報告將公開可能解決之道。
編譯葉心嵐
2007年01月11日 蘋果日報
