Arsenic in drinking water threatens up to 60 million in Pakistan

Arsenic in drinking water threatens up to 60 million in Pakistan

first_img Sign up for our daily newsletter Get more great content like this delivered right to you! Country B. K. Bangash/ASSOCIATED PRESS Villagers collect water from a broken water pipeline in the outskirts of Islamabad. By Giorgia GuglielmiAug. 23, 2017 , 4:15 PM Arsenic in drinking water threatens up to 60 million in Pakistan Jia You/Science Emailcenter_img “It’s a reminder that arsenic remains a serious public health threat in drinking water,” says Richard Johnston, a public health engineer at WHO in Geneva, Switzerland, who was not involved in the research. He hopes the predictive method can be applied to other areas of the world with similar geologies to Pakistan.Other experts hope that the study will motivate Pakistani authorities to test wells in high-risk areas and warn communities. “People should be aware that water in their well has high arsenic,” says Charles Harvey, a hydrogeologist at the Massachusetts Institute of Technology in Cambridge. If people are aware of the risks, they could use water from deeper aquifers that are in contact with older sediments, or invest in treating groundwater to remove arsenic.Peter Ravenscroft, a hydrogeologist and independent consultant based in Cambridge, U.K., says this work will help draw the attention of policymakers and aid agencies to the arsenic threat in Pakistan. “Maps like this have a big impact,” he says. It has been called the largest mass poisoning in history. After wells were drilled in Bangladesh and the rest of the Indian subcontinent in the 1970s, millions of people have been exposed to arsenic in drinking water. When leached into water from surrounding rocks and soil, the metal can—at high concentrations—cause skin lesions, cancer, cardiovascular diseases, and neurodevelopmental delays. Now, a study suggests Pakistan might be grappling with its own arsenic emergency, with up to 60 million people exposed to contaminated water.The extent of the problem first became clear in the 1990s, when a series of studies found high arsenic concentrations across the Ganges-Brahmaputra Delta. The World Health Organization (WHO) warned that 35 million to 77 million people in Bangladesh could be at risk of drinking water with unsafe levels of arsenic. And in 2014, WHO estimated that about 200 million people worldwide are exposed to concentrations exceeding the recommended limit of 10 micrograms per liter of water. Most live in Bangladesh, India, Vietnam, and Nepal.Previous studies had revealed that groundwater in some areas of Pakistan also contained high levels of arsenic. But the extent of those risks was unknown, says Joel Podgorski, an environmental scientist at the Swiss Federal Institute of Aquatic Science and Technology in Dübendorf  and lead author of the new study. Podgorski’s team started by measuring arsenic levels in groundwater samples collected from about 1200 wells throughout Pakistan at depths of 3 to 70 meters. Nearly two-thirds exceeded the WHO-recommended threshold, and extremely high concentrations—above 200 micrograms per liter—were found along the Indus River valley. The higher concentrations tended to occur in areas with higher soil pH and near sand and clay younger than 10,000 years. Older sediments have been exposed to so much water over geological time that most of their arsenic has already washed out to sea. Under specific chemical conditions, the arsenic in younger sediments can dissolve in water and contaminate it, Podgorski says. Next, the team created the region’s first risk map for arsenic, which shows the probability of dangerous concentrations in every part of the country. By estimating the number of people relying on groundwater for drinking, the team reports today in Science Advances that 50 million to 60 million people might use water that contains more than 50 micrograms per liter of arsenic, five times the WHO guideline.  Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Click to view the privacy policy. 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