Release and transport of contaminants in watersheds can have adverse effects on aquatic organisms and human health. Little attention, however, has been paid to chemical contamination of aquatic environments in arid regions by persistent organic pollutants. We analyzed the concentrations and distributions of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in waters of the Ili-Balkhash Basin, in arid central Asia. ΣOCP concentrations ranged from 4.02 to 122.80 ng L^–1 and ΣPAH concentrations were between 7.58 and 70.98 ng L^–1. On a global scale, OCP and PAH concentrations in waters of the Ili-Balkhash system were relatively low, with only a few exceptions, i.e., highest concentrations near cities and relatively high values in some headwater areas. Source identification revealed that the dichlorodiphenyltrichloroethanes (DDTs) may come from recent use, whereas endosulfans stem from historic applications. Lindane, a common insecticide, may be responsible for hexachlorocyclohexanes (HCHs). Low-molecular-weight PAHs, primarily originating from wood and coal combustion and petroleum-derived sources, were the primary components of PAHs in waters. Furthermore, the primary sources of PAHs at different sites were identified using a Positive Matrix Factorization model: 1) oil leakage (33.9%), 2) biomass burning (29.5%), 3) coal combustion (22.6%), and 4) petroleum-powered vehicles (14.1%). Agricultural, industrial and domestic activities are all potential pollution sources. Besides, contaminated headwater areas indicate that long-range transport has probably become a non-negligible mechanism for pollutant distribution. Risk assessment showed low to moderate toxicity for aquatic organisms, but no marked carcinogenic or non-carcinogenic risks for human health.

流域中污染物的释放和运输会对水生生物和人类健康产生不利影响。然而，很少有人关注持久性有机污染物对干旱地区水生环境的化学污染。我们分析了干旱中亚伊利-巴尔喀什盆地水域中有机氯农药（OCP）和多环芳烃（PAH）的浓度和分布。ΣOCP浓度范围为4.02至122.80 ng L ^–1，ΣPAH浓度范围为7.58至70.98 ng L ^–1。在全球范围内，伊利-巴尔喀什（Ili-Balkhash）系统水域中的OCP和PAH浓度相对较低，只有少数例外，即城市附近的最高浓度和某些源头地区的相对较高值。来源鉴定表明，二氯二苯基三氯乙烷（DDT）可能来自最近的使用，而硫丹则来自历史上的应用。林丹是一种常见的杀虫剂，可能与六氯环己烷（HCH）有关。低分子量多环芳烃主要来自木材和煤炭燃烧以及石油来源，是水中多环芳烃的主要成分。此外，使用正矩阵分解模型确定了不同地点PAHs的主要来源：1）漏油（33.9％），2）生物质燃烧（29.5％），3）煤炭燃烧（22.6％），4）石油动力车辆（14.1％）。农业，工业和家庭活动都是潜在的污染源。此外，受污染的源头地区表明，远距离迁移可能已成为污染物分配不可忽视的机制。风险评估表明，对水生生物具有中低毒性，但对人类健康没有明显的致癌或非致癌风险。