In the first days of spring， people flock to Lake Geneva’s tree-lined promenade1， their faces tilted towards the sun. Dior， Cartier and Rolex are among the high-end shopfronts2 overlooking the water.

春日伊始，人们纷纷涌向日内瓦湖畔绿树成荫的步道，仰头沐浴阳光。迪奥、卡地亚和劳力士等高端品牌店临水而立。

Rene Rottenberg， 75， has just finished his 400m swim—a ritual3 he repeats up to five times a week， even in midwinter. For the retired gynaecologist4， being able to swim in the crystal-clear water is the greatest luxury. “It’s just so fun，” he says. “The place is beautiful.”

75岁的勒内·罗滕伯格刚完成400米游泳——这是他雷打不动、每周多达五次的活动，即便仲冬时节也不例外。对于这位退休妇科医生来说，能在清澈的湖水中畅游是难得的莫大享受。他表示：“太开心啦。这地方美极了。”

Rottenberg is a member of Les Givres5 swimming club in the centre of the city. Dentists， secretaries， judges， teachers and retirees all brave the 8C water in their lunch break， emerging red and blotchy6 with cold. “You find everyone here，” says Rottenberg. They have lunch together before being swallowed back into the city.

罗滕伯格是位于市中心的凌霜游泳俱乐部的会员。每到午休时分，牙医、秘书、法官、教师和退休人员等各路会员不顾寒冷，跃入8摄氏度的水中，出水时冻得皮肤通红斑驳。“这里有形形色色的人。”罗滕伯格说。他们共进午餐后，便又隐没于都市洪流之中。

The sight of people launching themselves into an inner-city waterway would be unthinkable in most cities in Europe， the US and many other parts of the world.

在欧美乃至全球其他许多地方的大多数城市，人们跃入市中心河道这一情景是不可思议的。

Three-quarters of Britain’s rivers are in poor ecological health， according to data collected by thousands of citizen scientists in 2024， with experts describing the findings as “truly disturbing”. Pollution from water companies and agricultural runoff are driving the contamination， which affects all parts of the country， causing toxic algal blooms， mass die-offs of fish， and risks to human health.

2024年数千名公民科学家收集的数据显示，英国3/4的河流生态状况不佳，专家称这一发现“着实令人不安”。水务公司排污和农业径流加剧污染，影响英国各地，导致毒藻蔓生、鱼类大量死亡，并危及人类健康。

Yet across Switzerland， such swimming scenes are normal. This hasn’t always been the case. In the 1960s， Switzerland had among the dirtiest water in Europe， blighted7 by mats of algae， mountains of foam， scum8， and dead fish at the surface. For decades， swimming was banned in some rivers such as the Aare and Limmat on health grounds， and people could get ill if they swallowed the water.

在瑞士全境，这样的游泳场景却很寻常。但情况并非一向如此。1960年代，瑞士水质在欧洲位居最脏之列，深受水面飘浮的丛生藻类、成堆泡沫、浮渣和死鱼之害。数十年来，出于健康考虑，阿勒河和利马特河等河流禁止游泳，人若误吞河水可能会生病。

Raw sewage and industrial wastewater flowed directly into water bodies—in 1965 only 14% of the population was connected to a wastewater treatment plant. Today， it is 98%， and the country has a reputation for pristine swimming waters， sometimes referred to as its “blue gold”—and it’s all thanks to a complex network of sewage plants.

未经处理的污水和工业废水直接排入水体——1965年，仅14%人口的生活污水排入污水处理厂。如今，这一比例已达98%，瑞士也以水质纯净的游泳水域著称，这些水域有时被誉为瑞士的“蔚蓝流金”——这得益于繁密的污水处理厂网络。

A key driver of that transformation was a tragedy in the mountain resort of Zermatt in 1963， when a typhoid9 outbreak killed three people and made 437 others ill. Soldiers were deployed and schools turned into emergency hospitals as panic spread. Pressure grew on the government to clean up the waterways， found to be the source of the outbreak. In 1971， the treatment of wastewater was written into Swiss law.

推动这一转变的主因是1963年采尔马特山度假区发生的灾难，当时伤寒疫情暴发造成3人病亡、437人染病。