Single rainwater samples were collected in the city of Goma (~1,1 million inhabitants), eastern Democratic Republic of the Congo, from January to June 2013 to draw a baseline for rainwater chemical composition and quality as influenced by the permanent plume of Nyiragongo volcano. This was a better period for a baseline as the neighboring Nyamulagira volcano, only 15 km apart, had no important degassing from its central crater, and hence the recorded volcanic influence on the rainwater chemistry was solely from Nyiragongo's lava lake which has been active since May 2002. The baseline for the rainwater chemistry and quality is important for this highly populated region where rainwater is the unique potable water source for the inhabitants of many villages surrounding the volcanoes, and for some of the inhabitants of the city of Goma. Our results show that samples collected at the crater rim of Nyiragongo were more acidic with pH ranging from 3.70 to 3.82, while the majority of rainwater samples collected in downtown Goma city and to the northeastern zone of the volcano had pH close to 5.7; which represents the value for rainwater from unpolluted continental areas (Berner and Berner, 2012). However, the pH was as low as 3.93 to the west of Nyiragongo volcano because the volcanic plume is directed westward by the dominant local wind direction. The western part of the city of Goma as well as the small town of Sake and many villages (e.g. Rusayo, Mubambiro, Kingi, …) are located in this zone, and experience endemic fluorosis caused by high fluoride in the available water. The mean F⁻ in this zone was 0.38 mg/L, while the southern and northeastern zones had mean F⁻ concentrations on 0.44 and 0.01 mg/L respectively; even though concentrations higher than the WHO guidelines were found in few samples from the western zone (1.69 mg/L) and from the southern zone (3.44 mg/L). Compared to data from Cuoco et al. (2012) obtained during the Nyamulagira 2010 eruption, and from Balagizi et al.2017 and Liotta et al., 2017 obtained during the intense degassing of both Nyiragongo and Nyamulagira lava lakes; we have noted similarity in the spatial variation of the pH, but samples from the present study showed notable lower concentrations of major elements. This is the case for fluoride which is strictly of volcanic origin. For the other major elements, anthropogenic sources, mainly the traffic and wind-blown dust; or other non-volcanic natural sources influenced their concentrations. Thus, the anions (Cl⁻ and SO₄²⁻) and cations (Na⁺, K⁺, Mg²⁺, and Ca²⁺) from the present study are either lower compared to that previously reported in the literature for the Virunga, or are both comparable for the zones impacted by anthropogenic activities.

2013 年 1 月至 6 月，在刚果民主共和国东部的戈马市（约 110 万居民）收集了单个雨水样本，以绘制受尼拉贡戈火山永久羽流影响的雨水化学成分和质量的基线. 这是一个更好的基线时期，因为相距仅 15 公里的邻近 Nyamulagira 火山没有从其中央火山口进行重要脱气，因此记录的火山对雨水化学的影响仅来自自 5 月以来一直活跃的 Nyiragongo 熔岩湖2002. 雨水化学和质量基线对于这个人口稠密的地区很重要，那里的雨水是火山周围许多村庄的居民以及戈马市的一些居民的独特饮用水源。我们的结果表明，在尼拉贡戈火山口边缘采集的样品酸性更强，pH 值范围为 3.70 至 3.82，而在戈马市中心和火山东北部采集的大部分雨水样品的 pH 值接近 5.7；它代表了来自未受污染大陆地区的雨水的价值（Berner 和 Berner，2012 年）。然而，尼拉贡戈火山以西的 pH 值低至 3.93，因为火山羽流在当地主导风向的作用下向西吹。戈马市的西部以及 Sake 小镇和许多村庄（例如 Rusayo、Mubambiro、Kingi 等）都位于该地区，并且由于可用水中的高氟化物而导致地方性氟中毒。平均 F 而在戈马市中心和火山东北部收集的大部分雨水样本的 pH 值接近 5.7；它代表了来自未受污染大陆地区的雨水的价值（Berner 和 Berner，2012 年）。然而，尼拉贡戈火山以西的 pH 值低至 3.93，因为火山羽流在当地主导风向的作用下向西吹。戈马市的西部以及 Sake 小镇和许多村庄（例如 Rusayo、Mubambiro、Kingi 等）都位于该地区，并且由于可用水中的高氟化物而导致地方性氟中毒。平均 F 而在戈马市中心和火山东北部收集的大部分雨水样本的 pH 值接近 5.7；它代表了来自未受污染大陆地区的雨水的价值（Berner 和 Berner，2012 年）。然而，尼拉贡戈火山以西的 pH 值低至 3.93，因为火山羽流在当地主导风向的作用下向西吹。戈马市的西部以及 Sake 小镇和许多村庄（例如 Rusayo、Mubambiro、Kingi 等）都位于该地区，并且由于可用水中的高氟化物而导致地方性氟中毒。平均 F 93 在 Nyiragongo 火山以西，因为火山羽流在当地主导风向的作用下向西吹。戈马市的西部以及 Sake 小镇和许多村庄（例如 Rusayo、Mubambiro、Kingi 等）都位于该地区，并且由于可用水中的高氟化物而导致地方性氟中毒。平均 F 93 在尼拉贡戈火山以西，因为火山羽流在当地主导风向的作用下向西吹。戈马市的西部以及 Sake 小镇和许多村庄（例如 Rusayo、Mubambiro、Kingi 等）都位于该地区，并且由于可用水中的高氟化物而导致地方性氟中毒。平均 F⁻在该区域为 0.38 mg/L，而南部和东北部区域为平均 F ⁻浓度分别为 0.44 和 0.01 毫克/升；尽管在西部地区 (1.69 mg/L) 和南部地区 (3.44 mg/L) 的少数样品中发现浓度高于 WHO 指南。与 Cuoco 等人的数据相比。(2012) 在 Nyamulagira 2010 喷发期间获得，以及来自 Balagizi 等人 2017 年和 Liotta 等人，2017 年在 Nyiragongo 和 Nyamulagira 熔岩湖强烈脱气期间获得；我们注意到 pH 值空间变化的相似性，但本研究的样本显示主要元素的浓度显着降低。严格来自火山的氟化物就是这种情况。其他主要元素，人为来源，主要是交通和风扬尘；或其他非火山自然资源影响了它们的浓度。因此，阴离子（Cl⁻和 SO ₄ ^2- ) 和本研究中的阳离子（Na ⁺、K ⁺、Mg ²⁺和 Ca ²⁺）要么低于先前在 Virunga 文献中报道的值，要么在受人为活动影响的区域。