A Unique Monitoring Method for Fecal and Sewage-Derived Chemical Pollution Utilizing International Pellet Watch Approach.

This study established a unique approach to assess fecal contamination by measuring fecal sterols, especially coprostanol (5ß-cholestanol-3ß-ol, 5ß) and cholestanol (5α-cholestan-3ß-ol, 5α) and their ratio 5ß/(5ß + 5α) alongside triclosan (TCS) and methyl-triclosan (MTC) in beached plastic pellets across 40 countries. Coprostanol concentrations ranged from 3.6 to 8190 ng/g pellet with extremely high levels in densely populated areas in African countries. The 5ß/(5ß + 5α) ratio was not affected by the difference in residence time of pellets in aquatic environments, and their spatial pattern showed a positive correlation with that of sedimentary sterols, demonstrating its reliability as an indicator of fecal contamination. Pellets from populated areas of economically developing countries, i.e., Africa and Asia, with lower coverage of wastewater treatment exhibited higher 5ß/(5ß + 5α) ratios (∼0.7) corresponding to ∼1% sewage in seawater, while pellets from developed countries, i.e., the USA, Canada, Japan, and Europe, with higher coverage of modern wastewater treatment displayed lower ratios (∼0.5), corresponding to the first contact limit. Triclosan levels were higher in developing countries (0.4-1298 ng/g pellet), whereas developed countries showed higher methyl-triclosan levels (0.5-70 ng/g pellet) due to TCS conversion during secondary treatment. However, some samples from Japan and Europe displayed higher TCS levels, suggesting contributions from combined sewage overflow (CSO). Combination of 5ß/(5ß + 5α) and MTC/TCS ratios revealed extreme fecal contamination from direct input of raw sewage due to inadequate treatment facilities in some African and South and Southeast Asian countries.

An Optimized NMR Stripline for Sensitive Supercritical Fluid Chromatography-Nuclear Magnetic Resonance of Microliter Sample Volumes.

To optimize sensitivity, there has been an increasing interest in the miniaturization of NMR detectors. In our lab, a stripline NMR detector has been developed, which provides high resolution and is scalable to a large range of sample volumes. These features make it an ideal detector for hyphenated techniques. In this manuscript, we demonstrate a stripline probe, which is designed for combining supercritical fluid chromatography (SFC) experiments with NMR. It features a novel stripline chip, designed to reduce the signal from the contact pads, which results in an improved lineshape. An external lock circuit provides stability over time to perform signal averaging or multidimensional experiments. As proof of concept, we demonstrate the SFC-NMR technique with this stripline probe using a mixture of cholesterol and cholestanol, which is relevant for studying cerebrotendinous xanthomatosis. Additionally, this probe makes it possible to record high-resolution spectra of samples with a high spin density. This means that it is possible to directly observe shifts due to the nuclear demagnetizing field in the "homomolecular" case, which is challenging using conventional probes due to broadening effects from radiation damping.

Methyl Ether-Derivatized Sterols and Coprostanol Produced via Thermochemolysis Using Tetramethylammonium Hydroxide (TMAH).

Sterols are widely distributed in nature from lipids in organisms to sediments. As a conventional method, extraction and derivatization with TMS have been applied for sterol analysis, requiring a long preparation time for gas chromatography-mass spectrometry analysis. In this study, for sterol analysis, thermochemolysis using tetramethylammonium hydroxide (TMAH) was applied. This method performs hydrolysis and methylation simultaneously; thus, free and ether-bonding sterols can be analyzed as sterol methyl ethers in a relatively short time period. A sediment sample from a tideland (the Yatsu tideland, Japan) was analyzed using the TMAH method, and we detected more than 10 sterols, which include cholest-5-en-3ß-ol (cholesterol), 24-ethylcholest-5-en-3ß-ol (sitosterol), 24-methylcholesta-5,22E-3ß-ol (brassicasterol), 24-ethylcholesta-5,24(28)Z-dien-3ß-ol (isofucosterol), 4α,23,24-trimethyl-5α(H)-cholest-22E-en-3ß- ol (dinosterol), and 5ß(H)-cholestan-3ß-ol (coprostanol). The detection of the various sterols can be attributed to multiple natural and artificial sources around the Yatsu tideland. In this paper, the mass spectra of these sterols are provided together with an interpretation of their fragmentation patterns. Additionally, the fecal pollution in the Yatsu tideland is discussed in the context of the detection of coprostanol.

Identifying avian sources of faecal contamination using sterol analysis.

Discrimination of the source of faecal pollution in water bodies is an important step in the assessment and mitigation of public health risk. One tool for faecal source tracking is the analysis of faecal sterols which are present in faeces of animals in a range of distinctive ratios. Published ratios are able to discriminate between human and herbivore mammal faecal inputs but are of less value for identifying pollution from wildfowl, which can be a common cause of elevated bacterial indicators in rivers and streams. In this study, the sterol profiles of 50 avian-derived faecal specimens (seagulls, ducks and chickens) were examined alongside those of 57 ruminant faeces and previously published sterol profiles of human wastewater, chicken effluent and animal meatwork effluent. Two novel sterol ratios were identified as specific to avian faecal scats, which, when incorporated into a decision tree with human and herbivore mammal indicative ratios, were able to identify sterols from avian-polluted waterways. For samples where the sterol profile was not consistent with herbivore mammal or human pollution, avian pollution is indicated when the ratio of 24-ethylcholestanol/(24-ethylcholestanol + 24-ethylcoprostanol + 24-ethylepicoprostanol) is ≥0.4 (avian ratio 1) and the ratio of cholestanol/(cholestanol + coprostanol + epicoprostanol) is ≥0.5 (avian ratio 2). When avian pollution is indicated, further confirmation by targeted PCR specific markers can be employed if greater confidence in the pollution source is required. A 66% concordance between sterol ratios and current avian PCR markers was achieved when 56 water samples from polluted waterways were analysed.

Correlation between caffeine and coprostanol in contrasting Amazonian water bodies.

The evaluation of contamination by domestic sewage is relevant in the Amazon region; however, it has neither been well-developed nor accompanied by research or monitoring programs. In this study, caffeine and coprostanol as indicators of sewage were investigated in water samples from Amazonian water bodies that crisscross the city of Manaus (Amazonas state, Brazil) and cover regions with distinct main land uses such as high-density residential, low-density residential, commercial, industrial, and environmental protection areas. Thirty-one water samples were studied based on their dissolved and particulate organic matter (DOM and POM) fractions. Quantitative determination of both caffeine and coprostanol was carried out using LC-MS/MS with APCI in the positive ionization mode. The streams of the urban area of Manaus had the highest concentrations of caffeine (1.47-69.65 µg L-1) and coprostanol (2.88-46.92 µg L-1). Samples from the peri-urban Tarumã-Açu stream and from the streams in the Adolpho Ducke Forest Reserve showed much lower concentrations of caffeine (20.20-165.78 ng L-1) and coprostanol (31.49-120.44 ng L-1). Samples from the Negro River showed a wider range of concentrations of caffeine (20.59-873.59 ng L-1) and coprostanol (31.72-706.46 ng L-1), with the highest values found in the outfalls of the urban streams. Levels of caffeine and coprostanol were significantly positively correlated in the different organic matter fractions. The coprostanol/(coprostanol + cholestanol) ratio proved to be a more suitable parameter than the coprostanol/cholesterol one in low-density residential areas. Proximity to densely populated areas and the flow of water bodies appear to influence the caffeine and coprostanol concentrations, which was observed in their clustering in the multivariate analysis. The results indicate that caffeine and coprostanol can be detected even in water bodies that receive very low domestic sewage input. Therefore, this study revealed that both caffeine in DOM and coprostanol in POM represent viable alternatives for use in studies and monitoring programs even in remote areas of the Amazon, where microbiological analyses are often unfeasible.

Understanding common population markers for SARS-CoV-2 RNA normalization in wastewater - A review.

Wastewater monitoring and epidemiology have seen renewed interest during the recent COVID-19 pandemic. As a result, there is an increasing need to normalize wastewater-derived viral loads in local populations. Chemical tracers, both exogenous and endogenous compounds, have proven to be more stable and reliable for normalization than biological indicators. However, differing instrumentation and extraction methods can make it difficult to compare results. This review examines current extraction and quantification methods for ten common population indicators: creatinine, coprostanol, nicotine, cotinine, sucralose, acesulfame, androstenedione 5-hydroindoleacetic acid (5-HIAA), caffeine, and 1,7-dimethyluric acid. Some wastewater parameters such as ammonia, total nitrogen, total phosphorus, and daily flowrate were also evaluated. The analytical methods included direct injection, dilute and shoot, liquid/liquid, and solid phase extraction (SPE). Creatine, acesulfame, nicotine, 5-HIAA and androstenedione have been analysed by direct injection into LC-MS; however, most authors prefer to include SPE steps to avoid matrix effects. Both LC-MS and GC-MS have been successfully used to quantify coprostanol in wastewater, and the other selected indicators have been quantified successfully with LC-MS. Acidification to stabilize the sample before freezing to maintain the integrity of samples has been reported to be beneficial. However, there are arguments both for and against working at acidic pHs. Wastewater parameters mentioned earlier are quick and easy to quantify, but the data does not always represent the human population effectively. A preference for population indicators originating solely from humans is apparent. This review summarises methods employed for chemical indicators in wastewater, provides a basis for choosing an appropriate extraction and analysis method, and highlights the utility of accurate chemical tracer data for wastewater-based epidemiology.

Chemometric application in identifying sources of organic contaminants in Langat river basin.

Increasing urbanization and changes in land use in Langat river basin lead to adverse impacts on the environment compartment. One of the major challenges is in identifying sources of organic contaminants. This study presented the application of selected chemometric techniques: cluster analysis (CA), discriminant analysis (DA), and principal component analysis (PCA) to classify the pollution sources in Langat river basin based on the analysis of water and sediment samples collected from 24 stations, monitored for 14 organic contaminants from polycyclic aromatic hydrocarbons (PAHs), sterols, and pesticides groups. The CA and DA enabled to group 24 monitoring sites into three groups of pollution source (industry and urban socioeconomic, agricultural activity, and urban/domestic sewage) with five major discriminating variables: naphthalene, pyrene, benzo[a]pyrene, coprostanol, and cholesterol. PCA analysis, applied to water data sets, resulted in four latent factors explaining 79.0% of the total variance while sediment samples gave five latent factors with 77.6% explained variance. The varifactors (VFs) obtained from PCA indicated that sterols (coprostanol, cholesterol, stigmasterol, ß-sitosterol, and stigmastanol) are strongly correlated to domestic and urban sewage, PAHs (naphthalene, acenaphthene, pyrene, benzo[a]anthracene, and benzo[a]pyrene) from industrial and urban activities and chlorpyrifos correlated to samples nearby agricultural sites. The results demonstrated that chemometric techniques can be used for rapid assessment of water and sediment contaminations.

Tracking the historical urban and rural sources of fecal pollution in a South American tropical semi-arid region using sterols and endocrine-disrupting chemicals.

Sterols and endocrine-disrupting chemicals were analyzed in two dated sediment cores collected in the Jaguaribe river to determine the recent decades' influence of urbanization and agropastoral activities on the inputs of fecal pollution in a semi-arid region of Brazil. Stigmasterol and sitosterol were the most abundant of the 6 sterols examined in both cores, indicating an important contribution of organic matter from mangrove forests to the study region. Coprostanol presented a continuous increase in concentrations from the 1930s to the 2000s in one core, however, showing higher concentrations (>100 ng g-1) in the upper layers of both cores. The sterols diagnostic ratios indicated fecal pollution through both cores, especially from the 1940s to 1970s. The coprostanol levels followed the variations in population growth in the state of Ceará. Estriol and estrone were the most abundant estrogenic hormones found in both cores. These compounds are probably related to the intense livestock activities in the Ceará state, especially after the 1970s. The baseline levels of fecal sterols and estrogen hormones found in this study possibly represent a previous unimpacted scenario and may be used for future evaluations of fecal pollution from urbanization and livestock activities.

Steroid-based tracing of sewage-sourced pollution of river water and wastewater treatment efficiency: Dissolved and suspended water phase distribution.

In this work, the environmental distribution of steroid compounds and the level of sewage-derived contamination were assessed using sterol ratios in the confluence area of two major rivers in the Serbian capital, where raw sewage is discharged without any treatment. Special attention was paid to steroids partitioning between the dissolved and suspended phases of river and wastewater samples, since steroids tend to easily bind to particulate matter. The efficiency of sterol removal in two wastewater treatment plants in Serbia was also evaluated. Human/animal sterols coprostanol and cholesterol, and phytosterol ß-sitosterol were the dominant compounds in all water samples. The sterol abundance pattern in river water was different from that in raw sewage, indicating a more pronounced biogenic input, as well as greater impact of wastewater discharges on the composition of the suspended phase. Severe contamination of the investigated area was determined, with the Danube being more contaminated than the Sava River due to different hydrodynamic conditions leading to significantly higher sterol levels in the suspended particulate matter. It was also shown that the greater part of human/animal sterols and phytosterols present in river water samples (83.0 ±â€¯11.9 % and 87.1 ±â€¯15.2 %) and wastewater samples (92.1 ±â€¯6.8 % and 95.0 ±â€¯5.7 %) was bound to suspended material compared to the dissolved phase, emphasizing the need to consider and analyze both water phases in the tracing of steroid-based environmental pollution in order to obtain a realistic picture of steroid contamination and their fate in the aquatic environment. A high removal rate (>98 %) of coprostanol and cholesterol during wastewater treatment was determined and only the coprostanol/(coprostanol + cholestanol) ratio was found to be sensitive enough to be affected by an improvement in the quality of treated wastewater.

Determination of fecal contamination indicator sterols in an Australian water supply system.

This paper reports a reconnaissance survey of the concentrations of sterol compounds (as indicators of fecal contamination) in a large water supply system in southeast Australia comprising a network of rivers, channels, and drains. Levels of coprostanol and cholestanol were determined in surface water and bottom sediment using gas chromatography-mass spectrometry analysis across 17 strategic sampling sites and over 12 months. Clear differences in the levels of fecal contamination were observed among sites. Four sites routinely contained high levels of the fecal indicator sterols indicated from surface water and sediment sample analysis. Coprostanol concentrations at each location varied from 0 ng/L at the reference site to 11,327 ng/L in a surface water sample of a drain directly downstream of a knackery. The majority of the sites contained coprostanol in the range of 500 to 800 ng/L. Since no fecal-associated sterol compounds were detected at the external reference sites, these were assumed to be free from fecal contamination. Sewage water discharge and/or substantial water runoff maybe the principal factors contributing to fecal contamination of the supply drains and channels.

Coprostanol in Siak River sediments, E Sumatra, Indonesia.

To follow faecal pollution steroid compounds have been analysed in 106 sediment samples from the Siak River, E Sumatra, Indonesia. Coprostanol was detected in 40 of these. Contents ranged from 50 to 10,530 ng/g d.w. with a mean of 878 (TOC-normalised: range 7.4-393.0, mean 44.1 µg/g TOC). Total contents and the coprostanol/cholesterol ratio argue for a major contribution from untreated sewage which is also evident from field observations. The distribution along the river indicates the quantitatively dominant source to be the city of Pekanbaru with an estimated population of 1.5 million. Coprostanol contents decrease downstream indicating ongoing degradation either during transport or in the surface sediment. However, additional sources of coprostanol become evident further downstream. On the other hand, the 5ß/(5ß + 5α)-cholestan-3ß-ol ratio versus cholesterol and a ternary plot using C27 sterols suggest that plant sources also contribute to the sedimentary coprostanol due to its formation by bacteria in suboxic/anoxic sediments.

An elegant technology for ultrasensitive impedimetric and voltammetric determination of cholestanol based on a novel molecularly imprinted electrochemical sensor.

In this work, a novel molecularly imprinted electrochemical sensor (MIES) has been fabricated based on electropolymerization of a molecularly imprinted polymer (MIP) onto a glassy carbon electrode (GCE) modified with gold-palladium alloy nanoparticles (AuPd NPs)/polydopamine film (PDA)/multiwalled carbon nanotubes-chitosan-ionic liquid (MWCNTs-CS-IL) for voltammetric and impedimetric determination of cholestanol (CHO). Modifications applied to the bare GCE formed an excellent biocompatible composite film which was able to selectively detect CHO molecules. Modifications applied to the bare GCE were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (SEM). Under optimal experimental conditions, the sensor was able to detect CHO in the range of 0.1-60 pM and 1-50 pM by EIS and DPV, respectively. Moreover, the sensor showed high sensitivity, selectivity, repeatability, reproducibility, low interference and good stability towards CHO determination. Our records confirmed that the sensor was successfully able to the analysis real samples for determination of CHO.

Hypolipidaemic effect of maize starch with different amylose content in ovariectomized rats depends on intake amount of resistant starch.

The effect of amylose content on digestibility of starch in the small intestine and on the concentration of plasma lipid were studied in ileorectostomized rats and in ovariectomized rats, respectively. Seven kinds of starch with different amylose content (0, 27, 54, 62, 76, 79, 86 %) were used as test starch, which contained 0.4, 5.6, 37.1, 40.2, 45.6, 36.9 and 36.1 % resistant starch (RS), respectively. Rats were fed one of test diets containing 30 % test starch with different amylose content for 14 d in ileorectostomized and for 21 d in ovariectomized rats. Food intake was not significantly different among the groups. In ileorectostomized rats, the small intestinal starch digestibility decreased with increasing intakes of amylose and RS. In ovariectomized rats, body weight gain was lower on the higher amylose maize starch diets. The concentrations of plasma TAG and cholesterol decreased with increasing intake of RS. The concentrations of liver total lipids and TAG decreased with increasing intake of RS, but that of liver cholesterol did not. There was significant positive correlation between the level of sterol regulatory element-binding protein-1c mRNA and concentration of liver TAG. Total SCFA amount in the caecum increased logarithmically with increasing dry weight of caecal contents. The amount of bile acids in the small intestinal content and the excretions of bile acids and neutral steroids in faeces increased with increasing RS intake. These results show that starch rich in RS is more effective in preventing ovarian hormone deficiency-induced hyperlipidaemia.

Faecal steroid excretion in humans is affected by calcium supplementation and shows gender-specific differences.

BACKGROUND: Previous human studies on the effect of dietary calcium supplementation on faecal excretion of bile acids (BA) and faecal water concentrations of animal neutral sterols (NSt, cholesterol and its metabolites) lack detailed information about single BA and NSt. AIM OF THE STUDY: We investigated whether single BA and NSt in faeces and especially in faecal water are affected by calcium supplementation and whether this affects genotoxicity of faecal water. In addition, we differentiated between men and women with regard to the concentrations of BA and NSt in faecal water. METHODS: Thirty-one healthy volunteers consumed a calcium supplemented bread (1.0 g/day) and a placebo bread, respectively, for 4 weeks in a double-blind, randomised cross-over trial. Faeces were collected quantitatively for 5 days in the last week of each period. NSt and BA were analysed by GC-MS. RESULTS: Due to calcium supplementation faecal concentrations of lithocholic acid (LCA, 14%, P = 0.008), deoxycholic acid (DCA, 19%, P < 0.001) and 12 keto-deoxycholic acid (12 keto DCA, 29%, P = 0.049) significantly increased whereas BA concentrations in faecal water were only marginally affected. In contrast, concentrations of cholesterol (30%, P = 0.020) and its metabolites coprostanol (43%, P = 0.004), coprostanone (36%, P = 0.003), cholestanol (44%, P = 0.001) and cholestenone (32%, P = 0.038) in faecal water significantly decreased. Total NSt concentration in faecal water was found to be significantly higher in women compared to men (P = 0.018). The genotoxicity of faecal water was neither affected by calcium supplementation nor were there gender-specific differences. CONCLUSIONS: Dietary calcium supplementation diversely affects BA and NSt in faeces and in faecal water but does not influence the genotoxicity of faecal water in healthy adults.

Assessment of fecal sterols in Barigui River sediments in Curitiba, Brazil.

The Barigui River watershed is located in the metropolitan region of Curitiba, southern Brazil, passing through several neighboring counties. In recent years, due to growth and disorderly occupation along the river, in addition to lack of sanitation, the Basin suffered a very large inflow of untreated domestic sewage. Current programs to monitor the watershed use traditional physical-chemical parameters and generally the analysis is performed only with water samples. This study analyzes the presence of fecal sterols in sediment samples. Sediment samples were collected from six points along the river and the stanols were extracted, purified and analyzed by GC-MS. Eight compounds were analyzed, among sterols and ketones. The presence of coprostanol was also identified. Coprostanol is a stanol containing a large amount in human feces. It is found near sources of pollution and can be associated with contamination by domestic sewage. The results showed high concentrations of coprostanol, ranging from 0.25 to 196 mug g( - 1). The ratio of coprostanol and epicoprostanol, was below 0.20 at most stations, indicating that the sewage discharged into the river does not undergo prior treatment. Contamination by untreated sewage was also confirmed by ratios of isomeric forms of sterols and ketones 5beta/(5beta + 5alpha).

Sterol biomarkers and fecal coliforms in a tropical estuary: Seasonal distribution and sources.

The Sergipe River estuary has been subjected to a range of anthropogenic activities including food, plastic, textile, ceramic and metallurgical production plants along with domestic sewage inputs, all of which are of environmental concern. In this study, the levels of fecal coliforms (FC) in surface water samples and sterols in superficial sediment samples collected from the Sergipe River estuary were determined. Based on the FC concentrations, 58% of the water samples were considered Water Potentially Unusable (WPU) according to the United States Environmental Protection Agency (USEPA). Concentrations of coprostanol ranged from 13 to 1072 ng g-1, indicating a significant input of sewage at some points in the estuary. Principal Component Analysis (PCA) showed that there is no clear correlation between the coprostanol and coliform data, which may be due to the high resistance to degradation of coprostanol in sediments and to recent inputs of sewage at the water sample collection points.

Sewage contamination of Amazon streams crossing Manaus (Brazil) by sterol biomarkers.

Sewage pollution is a principal factor of decreasing water quality, although it has not been considered a real impact in Amazonia that is still considered a pristine environment around the world. Thus, this study aimed to assess the levels of sewage contamination in sediments from three streams crossing Manaus - a Brazilian city of 2,403,796 inhabitants in the heart of the Amazon rain forest. Cholesterol, cholestanol, brassicasterol, ergosterol, stigmasterol, ß-sitosterol, campesterol, stigmastanol, coprostanol, and epicoprostanol levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). The fecal indicator, coprostanol, was found in high concentrations (509-12 830 ng g-1) and high relative proportions (21-54%) in all samples collected in the Mindu stream that crosses many heavily populated districts of the city, and in the Quarenta stream that crosses the Industrial District of Manaus. The sediments of the Tarumã-Açu stream also presented coprostanol; however, concentrations (

Identification and significance of sterols in MSW landfill leachate.

The sterol content of leachate from two different landfills (labeled as landfill J and landfill R, respectively) at Wuhan, central China was examined by GC/MS. About 20 types of sterols were identified according to their mass spectra of TMS (trimethylsilyl derivates) ethers and their eluting orders. Three types of indices of sterols, namely the ratio of 5beta/(5beta+5alpha) stanol, the ratio of coprostanol/epicoprostanol and the ratio of coprostanol/cholesterol, were used to assess and cross-validate sterol sources. The results showed that landfill R suffered faecal pollution while there are complex sterol sources in landfill J. The ratios of cholesterol/(chloesterol+cholestanol) were 0.24 in landfill R and 0.32 in landfill J, indicating cholesterol reduction in both landfills. C29 sterols consisted of 58% of total sterols in landfill J leachate. The sources for the landfill leachate included not only allochthonous domestic wastes, but biodegradation products of autochthonous wastes in the landfills.

[Indicators of water microbial pollution: problems and perspectives]. / Indicatori di qualità microbiologica delle acque: problemi e prospettive.

Conventional indicators of fecal contamination provide a precious contribution in evaluating water microbiological quality. In recent years some important issues have sprung up which have risen doubts about their reliability and have suggested a revision of their function. In developed countries, where the law regarding water quality is very strict, there have been several outbreaks, even though conventional indicators of fecal pollution pointed an appropriate microbiological quality. These outbreaks have been imputed to new pathogenic microorganisms which are often characterized by a great resistance to disinfection treatments than conventional indicators. In order to obtain an appropriate microbiological quality of waters, various approaches have been started such as the Water Safety Plans by World Health Organization the revision of the functions of suitable indicators (of the water quality), the setting up of specific methods either for pathogen microorganisms and for a quick surveying of an inadequate microbiological water quality.

Organic contamination as a driver of structural changes of hydroid's assemblages of the coral reefs near to Havana Harbour, Cuba.

Hydroid assemblage's responses to organic contamination were evaluated using sedimentary sterols as explanatory variables. At seven coral reef sites in the Havana west coast, hydroids were collected along three 10 m × 1 m, 10 m deep transects. Five sterols were analysed, i.e., coprostanol, an indicator of faecal contamination, and cholestanol, cholesterol, stigmasterol and brassicasterol, indicators of biogenic organic matter inputs. The sampling sites were classified by level of contamination. A total of 65 species comprised the hydroid assemblages. Hydroids community abundance and richness decreased in the contaminated sites. Coprostanol had the highest relative importance for these variables and also for Plumularia floridana and Clytia gracilis abundances. Obelia dichotoma and Halecium bermudense were relatively abundant in the contaminated sites. The results indicate that faecal contamination negatively affected the hydroid assemblages, highlighting the importance of integrated biological and chemical indicators to evaluate the environmental conditions of the Havana coral reef.