再不注意保护，人类或将“后继无人”？
一场笼罩全球人类的繁衍危机，正在悄然袭来。
近日，有流行病专家发出警告，当前各类化学物质正在严重侵害男性精子的健康，人类或将在不久的将来失去自然繁殖能力。
这并不是危言耸听。纽约西奈山伊坎医学院的生殖流行病学家斯温通过研究发现，全球范围，男性精子的数量正在以惊人的速度衰退。根据1973-2011年间全球4.2万人流行病学调查数据显示，在过去的四十年，西方国家男性的精子数量锐减超过一半，且下降趋势强劲。
我国情况也不容乐观。根据世界卫生组织近10年的评估数据，我国男性的精子数量与三四十年前相比也已大幅降低，仅剩原来的1/4左右。
按照这个势头发展下去，斯温预计，到2045年，精子中位数将降至零，届时人类将面临“后继无人”的重大考验。
The world is facing an impending fertility crisis, experts warn.
Diminishing sperm counts and physical changes in men and women due to hormone-disrupting chemicals in products are threatening human survival, writes Epidemiologist Shanna Swan.
'If you look at the curve on sperm count and project it forward — which is always risky — it reaches zero in 2045,' Swan told Axios last month.
Swan's findings were first widely circulated in 2017, when she served as the senior author of a paper that examined 185 studies of nearly 43,000 healthy men in Western countries and found that total sperm count fell 59 percent between 1973-2011.
斯温表示，现代人的生活方式和化学物质正在逐步侵蚀人类的性发展和生育能力。
在众多影响精子数量的因素中，以日常生活中人们经常接触的化学物质为首。他们会干扰人体荷尔蒙的正常分泌，降低精子活力。
*全氟 烷基 物（Perfluoroalkyl substances）
属于人造化学物质，可消除在锅碗瓢盆、地毯、衣物以及鱼类和其他动物中发现的污渍。作为一种“永久性化学物质”，全氟烷对人类和环境具有长远危害性。
Man-made chemicals that repel stains and water found in pots and pans, carpets, clothing, and in fish and other animals. PFAS never disintegrate and can be found in major water supplies.
* 邻苯二甲酸 酯（Phthalates）：
主要做为增塑剂（ 增塑剂 ）使用，添加到塑胶中以增强弹性、透明度、耐用性和使用寿命。它们多被添加在洗涤剂、尿布、地板、指甲油、玩具中。此前在进行动物研究时，科学家就发现邻苯二甲酸酯类污染物会对动物胚胎发育造成损害，容易导致先天畸形和生殖问题。
Chemicals used to make plastic harder to break. They can be found in detergent, diapers, flooring, nail polish, toys and many other products. Phthalates have been found in animal studies to cause birth defects and reproductive problems.
*对羟基苯甲酸酯 （Parabens）
是一类用在化妆品及药品工业中的防腐剂，有时也被用在食品添加剂中，多用于洗发水、洗面奶、保湿剂、除臭剂，防晒霜、牙膏和化妆品中。已有研究表明，对羟基苯甲酸酯能够模拟雌激素，可能会对内分泌造成干扰。
Chemical preservatives that mimic the hormone estrogen. They can be found in shampoo, conditioner, face cleansers, moisturizers, deodorants, sunscreen, toothpaste and cosmetics.
这些化学物质已经“无孔不入”地渗透进我们的生活，并通过增加或减少人们的正常激素水平，对男性精子浓度和活力造成干扰。
斯温强调，这些“环境激素”不仅会影响男性精子，也会促进女性的性早熟，导致女性卵子质量下降，甚至造成流产等不良后果。
为此，斯温呼吁社会各界能够尽早行动起来，避免不当生活方式，降低化学物质对人类的侵害，保护我们的生育能力。
This can result in decreased sperm concentrations, decreased sperm motility, and genital abnormalities, according to the Environmental Working Group.
Swan's findings were first widely circulated in 2017, when she served as the senior author of a paper that examined 185 studies of nearly 43,000 healthy men in Western countries and found that total sperm count fell 59 percent between 1973-2011.
Women have also been impacted by increased chemicals in the environment. Around the world, the number of births per woman has fallen from 5 in 1960 to 2.4 in 2018, according to the World Bank.