Pregnant women and their fetuses represent susceptible populations to environmental contaminants. Exposure to polycyclic aromatic hydrocarbons (PAHs) among pregnant women may contribute to adverse birth outcomes such as preterm birth. Multiple previous studies have assessed airborne sources of PAHs among pregnant women but few have measured urinary PAH metabolites which can capture total exposure through multiple routes. The aim of this study was to bridge this knowledge gap by assessing longitudinal urinary PAH metabolite concentrations over two time points in pregnancy cohorts in Boston (N = 200) and Puerto Rico (N = 50) to better understand exposure distributions throughout pregnancy and how they relate to demographic factors. Urine samples were analyzed for 1-NAP, 2-NAP, 2-FLU, 1-PHE, 2,3-PHE, 4-PHE, 9-PHE, and 1-PYR. Concentrations of 2-NAP, 1-PYR, and 4-PHE were higher in Puerto Rico, while all other metabolites were present in higher concentrations in Boston. In Puerto Rico, intraclass correlation coefficients (ICC) were weak to moderate, ranging from 0.06 to 0.42. PAH metabolite concentrations were significantly higher among younger, heavier (except 1-NAP and 9-PHE), and less educated individuals in Boston only. Consistent significant associations between PAH concentrations and measured covariates were not found in Puerto Rico. Our results suggest that potentially important differences in PAH exposure exist between these two populations. Additionally, our results indicate that multiple urinary measurements are required to accurately assess PAH exposure throughout pregnancy.

This study investigates the occurrence of six phthalates and distribution of the three most-detected phthalates in the karst region of northern Puerto Rico (KRNPR) using data from historical records and current field measurements. Statistical data analyses, including ANOVA, Chi-Square, and logistic regression models are used to examine the major factors affecting the presence and concentrations of phthalates in the KRNPR. The most detected phthalates include DEHP, DBP, and DEP. At least one phthalate specie is detected above DL in 7% of the samples and 24% of the sampling sites. Concentrations of total phthalates average 5.08 ± 1.37 μg L−1, and range from 0.093 to 58.4 μg L−1. The analysis shows extensive spatial and temporal presence of phthalates resulting from dispersed phthalate sources throughout the karst aquifers. Hydrogeological factors are significantly more important in predicting the presence and concentrations of phthalates in eogenetic karst aquifers than anthropogenic factors. Among the hydrogeological factors, time of detection and hydraulic conductivities larger than 300 m d−1 are the most influential factors. Persistent presence through time reflects continuous sources of phthalates entering the aquifers and a high capacity of the karst aquifers to store and slowly release contaminants for long periods of time. The influence of hydraulic conductivity reveals the importance of contaminant fate and transport mechanisms from contamination sources. This study improves the understanding of factors affecting the spatial variability and fate of phthalates in karst aquifers, and allows us to better predict their occurrence based on these factors.

Caribbean islands, including Puerto Rico, are biodiversity hotspots threatened by microplastics (<5 mm). Little is known about the extent of microplastic pollution in coastal sandy beaches of Puerto Rico. Sand from six northern beaches was collected in the high tide line to determine microplastic abundance (0.3–4.75 mm). Península La Esperanza, the most polluted beach, exhibited higher average abundance (17 items/kg dw) and diversity. High urbanization, industrial/port activities, and riverine input are likely sources of plastic debris on this beach. The other beaches showed lower and similar average abundance (3 to 7 items/kg dw) despite having distinct potential point and non-point sources. Overall, fibers (40%), fragments (28%) and foams (27%) predominated (n = 102 particles). Results showed comparable levels to other world beaches, some classified as highly contaminated, but only when transforming units to items/m². Preliminary ATR-FTIR analysis identified mainly polyethylene. It is imperative to have plastics source reduction through waste management.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous, synthetic anthropogenic chemicals known to infiltrate and persist in biological systems as a result of their stability and bioaccumulation potential. This study investigated 15 PFAS, including short-chain carboxylic and sulfonic acids, and their presence in a threatened herbivore, the West Indian manatee (Trichechus manatus). Seven of the 15 PFAS examined were detected in manatee plasma. Perfluorooctanesulfonic acid (PFOS) (ranging from 0.13 to 166 ng/g ww) and perfluorononanoic acid (PFNA) (ranging from 0.038 to 3.52 ng/g ww) were detected in every manatee plasma sample examined (n = 69), with differing medians across sampling sites in Florida, Crystal River (n = 39), Brevard County (n = 18), Everglades National Park (n = 8), and four samples (n = 4) from Puerto Rico. With an herbivorous diet and long life-span, the manatee provides a new perspective to monitoring PFAS contamination.

Ascidians are an ideal taxon to study invasion processes: they require anthropogenic introduction vectors for long-distance dispersal, are easy to collect and monitor, and are abundant on artificial substrates. In March 2019 we surveyed 11 harbors around Puerto Rico and recorded 47 ascidian species. Eleven of these were only identified to the genus level or above based on morphological or genetic characterization. The remaining 36 species were classified as: 11 introduced (7 with worldwide distributions), 13 cryptogenic, and 12 native. We report the occurrence of Phallusia cf. philippinensis in the Atlantic for the first time. Ascidian community structure did not differ significantly across geographic locations and distances between marinas, while marina size had a significant effect on species richness and composition. Stakeholder involvement and periodic monitoring efforts are essential to detect the arrival of new species and the spread of already introduced ones to natural habitats.

There has been an increase in the scale and frequency of coral bleaching around the world due mainly to changes in sea temperature. This may occur at large scales, often resulting in significant decline in coral coverage. In order to understand the molecular and cellular basis of the ever-increasing incidence of coral bleaching, we have undertaken a comparative proteomic approach with the endangered Caribbean coral Acropora palmata. Using a proteomic tandem mass spectrometry approach, we identified 285 and 321 expressed protein signatures in bleached and unbleached A. palmata colonies, respectively, in southwestern Puerto Rico. Overall the expression level of 38 key proteins was significantly different between bleached and unbleached corals. A wide range of proteins was detected and categorized, including transcription factors involved mainly in heat stress/UV responses, immunity, apoptosis, biomineralization, the cytoskeleton, and endo–exophagocytosis. The results suggest that for bleached A. palmata, there was an induced differential protein expression response compared with those colonies that did not bleach under the same environmental conditions.

The level of fecal pollution in 17 sites in Puerto Rico was determined by Escherichia coli (E. coli) enumeration using an enzyme substrate medium and Quanti-Tray®/2000. Human fecal pollution was identified using an enzyme-linked immunosorbent assay for the detection of carbamazepine (CBZ) and quantitative polymerase chain reaction (qPCR) detection of the human Bacteroides marker, HF183. Carbamazepine was detected in 16 out of 17 sites, including Condado Lagoon, a popular recreational area. Elevated E. coli levels (>410CFU100mL−1) were detected in 13 sites. Average CBZ concentrations ranged from 0.005μgL−1 to 0.482μgL−1 and 7 sites were positive for HF183. Higher CBZ concentrations were associated with the detection of HF183 (Mann–Whitney test; U=42.0; df=7; 1-tailed P value=0.013). This was the second study to determine surface water concentrations of CBZ in the Caribbean and the first in Puerto Rico.

Land based sources of pollution have the potential to adversely impact valuable coral reef ecosystems. In Guánica Bay (Puerto Rico) sediment samples collected and analyzed in 2009 demonstrate unusually high concentrations of total chlordane, total PCBs, nickel and chromium. A variety of other contaminants (total DDT, total PAHs, As, Cu, Hg, and Zn) were also at levels which may indicate sediment toxicity. With the exception of chromium, all of these contaminants were detected in coral tissues (Porites astreoides), although it is unclear at what level these contaminants affect coral health. PCBs and chlordane are environmentally persistent and likely represent legacy pollution from historical uses in close geographic proximity to the Bay. We hypothesize that the high nickel and chromium levels are due to a combination of naturally high Ni and Cr in rock and soils in the watershed, and enhanced (human driven) erosional rates.

Fecal pollution in the coastal marine environments was assessed at eleven sampling locations along the Georgia coast and Trinidad, and nine sites from Puerto-Rico. Membrane filtration (EPA method 1604 and method 1600) was utilized for Escherichia coli and enterococci enumeration at each location. Quantitative polymerase chain reaction (qPCR) amplification of the 16S ribosomal RNA gene was used to determine the presence of the Helicobacter pylori in marine samples. There was no significant correlation between the levels of E. coli, enterococci and H. pylori in these water samples. H. pylori was detected at four of the 31 locations sampled; Oak Grove Island and Village Creek Landing in Georgia, Maracas river in Trinidad, and Ceiba Creek in Puerto Rico. The study confirms the potential public health risk to humans due to the widespread distribution of H. pylori in subtropical and tropical costal marine waters.

The goal of this study was to determine the potential for Enterohemorrhagic Escherichia coli O157:H7 (EHEC) contamination in tropical marine waters. Samples were collected from urban, suburban, and rural sites around the islands of Puerto Rico and The Republic of Trinidad and Tobago. Quantification of E. coli and EHEC was evaluated using MI plates and qPCR. EHEC was detected in six sites in Puerto Rico: West of La Parguera Town, Boquilla, Oro Creek, Fishers Association, Joyuda Lagoon, and Boqueron Wetland Creek and in two rural sites in Trinidad: Balandra Bay and Quinam Bay. Plate count enumeration of E. coli was not a reliable indicator for the presence of EHEC. The sites where EHEC was detected on both islands are used for recreational bathing, water sports and recreational/commercial fisheries and therefore pose a public potential health risk.