Wastewater surveillance represents an alternative approach to regulating contamination and the early detection of infectious agents and outbreaks of diseases of public health importance. This study evaluated domestic wastewater effects on recreational waters in estuarine and seawater bodies in Guayas and Santa Elena provinces in Ecuador, South America. Fecal indicator bacteria (thermotolerant coliforms) served as key indicators for evaluation. Physical, chemical, and microbiological quality markers following the Ecuadorian environmental quality standard and the discharge of effluents to the water resource were analyzed. Samples were collected from 44 coastal sites and 2 oxidation lagoons during the dry and rainy seasons of 2020 and 2021, respectively. SARS-CoV-2 RNA was detected in samples with higher E. coli concentrations using reverse transcription quantitative PCR to detect the genes N and ORF1ab. All samples analyzed for SARS-CoV-2 showed Ct ˂ 40 for at least one gene. Four samples showed at least 20 genome copies of gene N per reaction. These were at an artisanal fishing port, an estuarine area (Palmar), a recreational bay, and an oxidation lagoon. A moderate correlation was found between SARS-CoV-2 RNA, thermotolerant coliform and E. coli (p-value ≤ 0.0037), and a strong and positive correlation between thermotolerant coliform and E. coli. (p-value ≤ 0.00001), highlighting the utility of these established parameters as a proxy of the virus. Significant differences were found in the concentrations of thermotolerant coliforms between seasons (p-value = 0.016) and sites (p-value = 0.005). The highest levels of coliforms were found in the dry season (63000 MPN/100 mL) in Anconcito and during the rainy season (14000 MPN/100 mL) at Esterillo in Playas County. It is recommended that the decentralized autonomous governments of the surveyed provinces in Ecuador implement urgent corrective actions and establish medium-term mechanisms to minimize a potential contamination route. Additional parameters must be included in the monitoring, such as Enterococcus and intestinal parasites, due to their public health implications. In the oxidation lagoons, maintenance actions must be carried out, including the dissolution of sediments, an increase in water retention times, and in situ treatment of the sludge, to improve the system’s performance.

Since 2006, The Olduvai Paleoanthropology and Paleoecology Project (TOPPP) is conducting intensive research in a number of classical and newly discovered sites throughout the sequence of Olduvai Gorge, in Tanzania. Over these fifteen years of intense fieldwork, efforts have mostly focused on the Oldowan and Acheulean evidence located in Bed I and Bed II, but also intended on more recent and less known resources of the archaeological record, such us those located in the Ndutu beds. In this work we present a synthetic and comprehensive view of the most significant scientific contributions produced by our team in the fields of lithic technology and paleo-economic studies, including: the remarkable enlargement of our knowledge on the technological behaviors undertaken during the Oldowan, as recorded in the various sites recently discovered within the Zinj paleosol (Bed I); the characterization of the oldest Acheulean in the Olduvai basin (and one of the earliest evidence of this techno-complex in East Africa) after the discovery by our team of the exceptional site of FLK West (Lower Bed II); new insights into the enduring debate of the techno-functional meaning of the Developed Oldowan/Acheulean interface through the re-excavation of various classical sites located in Middle and Upper Bed II, such as SHK, TK and BK, and the confirmation of the Acheulean ascription of their lithic assemblages; the discovery of a number of MSA sites, such as VCS and DGS, that confirm the significance of the MSA record in the Olduvai basin and nearby. (C) 2022 Elsevier Masson SAS. All rights reserved.

The FLK West sequence is divided into six fluvial stratigraphic levels, each of which provided archaeological materials. In the present paper we outline the major similarities and differences displayed by the lithic assemblages in FLK W, particularly the lower assemblages, which have yielded more objects than the upper ones. The differences noted in the absence-presence and frequency of LCTs may be explained in occupational terms, while the similarities in raw material selection, core reduction and flake retouching patterns indicate homogeneous cultural decisions and cognitive skills. We conclude that these assemblages were likely formed by the same hominin group or taxon and, therefore, the assemblage variability registered would correspond to different expressions of the same economic structure.

In this paper, we present the results of new archaeological and geological research carried out in SHK Extension, a new site excavated within the SHK fluvial complex (Bed II , Olduvai Gorge). The paper describes the stratigraphy of the site and its correlation with our excavation in SHK Main Site, showing that overbank archaeological accumulations in both areas are synchronous and form part of the same fluvial palaeo‐landscape. On the basis of the archaeo‐stratigraphical analysis performed, mainly geared towards defining high‐resolution chrono‐stratigraphical frameworks within the deposit, we report the results of a technological study of the lithic collection sorted by archaeo‐units, an assessment of the integrity of the main accumulation and an exhaustive lithic refitting programme. The archaeological sequence at SHK Extension, consisting of three archaeo‐units, preserves a high‐density patch of lithics and fossil bones (Level B2), on an overbank setting, isochronous with the SHK Main site. The high percentage of small lithic remains and bones, large number of fresh archaeological materials, and the identification of several refit sets support the integrity of the anthropogenic accumulation documented in Level B2. The main technological trait of the lithic assemblage from this level is the preservation of a qualitatively significant sample of large flakes and LCT s. The technological behaviours observed in SHKE , in the framework of the SHK complex, confirm that the complex web of inter‐assemblage variability during Bed II times operated also in very close fractions of the same palaeo‐landscape. This reinforces the idea that subtle functional parameters must be taken into account in our current assessment of the Developed Oldowan/Acheulean interface.

Core preparation has been documented in Developed Oldowan assemblages dated between 1.5–1.3 Ma. However, its correct identification and significance is a matter of debate. In order to shed light on this issue, this paper attempts to reconstruct the flake production processes of the lithic assemblages currently recovered in SHK and BK at Olduvai Gorge (Tanzania). The methodological approach applied for the study of these two classical Developed Oldowan sites is based on the analysis and classification of flaking cores through detailed diacritical and technological descriptions, regardless of aprioristic morphological considerations. The flake production processes identified in both assemblages exhibit great technological homogeneity. The most remarkable difference between them is linked with divergences in flake size production. Core rotation and elongation of the perimeter of the flaked surface were the main technical actions implemented to manage core reduction, and seem to be related to reduction intensity. Core preparation, specifically striking platform preparation, was also applied, but to a minor extent, and was linked with a more effective management of blank reduction. It was not carried out through rigid technical and geometric schemes, and the products obtained were not predetermined. Nevertheless, its mere presence in Developed Oldowan sites is very suggestive, as it confirms a strong relationship between the Developed Oldowan and early Acheulean assemblages.

This paper presents a detailed taphonomic study of the faunalassemblage from FLK West (Olduvai Gorge, Tanzania), a site with an Acheulean component that dates to 1.7 Ma. The faunal sample analysed here is distributed in different archaeological levels and is associated with a significant lithic accumulation including several large format tools and handaxes. The fauna indicates the proliferation of open environments similar to those found in other Bed II and late Bed I sites. Evidence of anthropogenic activity (e.g. defleshing activities and marrow consumption) has been identified in the form of cut and percussion marks. A photogrammetric and morphometric analysis suggests that these marks were produced with quartzite flakes and not with handaxes. Evidence of interaction with carnivores was also noted; tooth marks were observed on some bones. Such interaction indicates the existence of competition between humans and carnivores for the same ecological niche, and might lead us to reflect on the survival strategies of Lower Pleistocene hominins.

The Acheulean materials documented in FLK West dated c. 1.7 Ma. are the focus of the present work. An original techno-functional approach is applied here to analyze the origin of Acheulean tools. According to the results, these tools were employed in different functional contexts in which tasks of different durations that transformed resources with different resistances were carried out. The exploitation of large and resistant resources suggests that the economic mechanism governing the manufacture of these tools was an increase in the demand of the work load. The decision processes underlying the production of these tools have thus an evident functional motivation. However, the presence of a refined handaxe in the studied sample indicates that the design form and production principles of handaxe manufacture were the result of an abrupt emergence rather than a long gradual development. The integration of mechanical and ergonomic investigation in our research has been crucial to explain how a core-and-flake industry gave way to a technology based on the production of large and heavy shaped tools.

Taphonomic analysis carried out at BK4b has provided compelling evidence for megafaunal acquisition and consumption, and the amount of meat that hominins consumed is far greater than documented at any other early Pleistocene site. The aim of the present work is to characterize the lithic assemblage associated with such a special subsistence context. The results presented here show that the bulk of the technological process was largely devoted to producing in-site small quartz flakes motivated by an imperative demand for durable cutting edges. Conversely, the operational sequence aimed at producing LCTs played a secondary role and is represented by different and isolated fractions. The quality of the cutting edges of quartz flakes may explain the preferential use of quartz at BK4b for flake production. These techno-economic strategies are likely connected with the exploitation and consumption of carcasses (butchering technology), but other subsistence activities were carried out besides butchery. In sum, we can conclude that the higher demand of cutting edges that presumably required a recurrent megafaunal exploitation at BK4b was largely satisfied by the production of small flakes rather than LCTs.

The present work explores the production and functional relationships that may exist between bipolar cores and spheroids in Olduvai Gorge. Percussion experiments have been conducted to determine: if the bipolar technique is an adequate solution to split large and heavy quartz blocks into cuboid-shaped fragments, and in which percussion activities those bipolar fragments are modified from cuboid to spherical shape. In light of the results achieved, it can be concluded that: the bipolar technique is the most efficient technique to produce portable and manageable cuboid-shaped slab fragments, and bipolar cuboid-shaped fragments can be modified to sub-spherical shape through intensive percussive processes. The associations established between use patterns and functional parameters have allowed us to suggest that food pounding is the most plausible functional context for such shape modification.