Occurrence, fate and ecological risks of phthalate esters and bisphenol A in coastal wastewater discharges

Abstract

This study examines the occurrence and ecological risks of phthalate esters (PAEs) and bisphenol A (BPA) in raw urban wastewater from Bushehr, a coastal city in the northern Persian Gulf. PAEs, used as plasticizers, and BPA, found in various consumer products, are endocrine disruptors that pose environmental and health threats. The research evaluates the concentrations, distribution, and sources of these pollutants and assesses their ecological risks. Wastewater samples were collected from six discharge stations along the Bushehr coastline between February and April 2023. Using gas chromatography-mass spectrometry (GC-MS), seven PAE compounds, including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP), and di-octyl phthalate (DOP), alongside BPA were analyzed. DEHP emerged as the dominant PAE, with concentrations ranging from 19.67 to 39.75 µg/L, while BPA levels ranged from 0.10 to 2.50 µg/L, peaking at Rishehr Park. Ecological risk assessment, conducted using the risk quotient (RQ) method, revealed that DEHP posed a high ecological risk (RQ > 1) to sensitive aquatic species. These findings highlight the urgent need for improved wastewater treatment and pollution control to safeguard marine ecosystems and public health. The study contributes valuable insights into the contamination levels and sources of PAEs and BPA in the northern Persian Gulf, advancing the understanding of regional marine pollution and its ecological impacts.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-025-25697-8.

Introduction

The oil and petrochemical industry, shipping, dredging, mining, residential, fishing, agriculture, ballast water discharging, and extremely hazardous substances input are the critical environmental pressures on marine ecosystems^1–8. Endocrine-disrupting chemicals (EDCs) such as phthalate esters (PAEs) and bisphenol A (BPA) are considered emerging contaminants that harm human health, aquatic life, and the environment^9–11. Among these, PAEs represent one of the most prevalent and widely studied groups of EDCs due to their extensive industrial applications and environmental persistence. PAEs have been used as additives, humectants, plasticizers, antifoaming agents, and carriers in different industrial products^12,13. PAEs are commonly used in many sources such as household materials (house fittings, garments, cosmetic products, children’s dolls, packaging), building materials, industrial products (paints and varnishes, adhesives, greases, polishes, washers, electronics, toners, pesticides, insecticides, fertilizers), and others (i.e., medicines, medical instruments)^11,14,15. PAEs are identified in the environment at different concentration levels after their discharge into aquatic environments^16–19. Six PAE compounds, including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP), and di-octyl phthalate (DOP), are on the priority list of the United States Environmental Protection Agency (US EPA) due to their persistence, bioaccumulation, and endocrine-disrupting potential^19,20.

The health threats posed by PAEs and their potential ecotoxicological effects have been identified^21–23. Various health problems, such as allergies, asthma, an abnormal reproductive system, and reproductive failure, have been linked to PAE exposure^11,24. Different pathways, including oral exposure, inhalation, skin contact, and ingestion, are the main human exposure routes to PAEs^11,25,26. PAEs may exist in different environmental matrices/samples such as air, soils, sediments, surface water, and wastewater¹¹. Wastewater and sewage effluents are the main routes that release PAEs into the environment²⁷. Thus, raw wastewater represents an important source for the release of PAEs into the environment, such as receiving water bodies^21,28–30, which is an increasingly severe threat to global public health and has become a concern. Therefore, it is vital to determine the level of PAEs in water to protect the aquatic ecosystem and their consequent ecological risk to marine biota.

BPA is another persistent organic and emerging contaminant identified in aquatic environments in different concentrations^31,32. Regarding the noticeable estrogenic and/or anti-androgenic potential of BPA in humans and wildlife, as well as its toxic effects on brain and behavioral development and mammary glands in diverse organisms, this chemical is categorized as an EDC [9]. In 2010, the US EPA included BPA on its Concern List as a compound that may risk harming the environment (Bisphenol A Action Plan, 2010). Effluent discharge from municipal wastewater treatment plants (WWTPs), landfill leachates, burning of domestic waste, and degradation of plastic litter are the primary postconsumer sources of this chemical^9,33,34. BPA enters marine environments through untreated wastewater^33,35. Therefore, the eco-toxicological effects of BPA are a crucial issue, and it is important to assess the environmental risks caused by this chemical³⁶.

The presence of emerging contaminants such as PAEs and BPA in aquatic environments has become a growing concern due to their widespread use, persistence, and potential ecological and human health risks. These compounds are commonly found in various industrial and consumer products and are frequently detected in municipal wastewater. Chemical analysis methods for identifying and quantifying these contaminants in untreated urban wastewater are still under development, and implementing effective quality control measures remains a challenge.

To the best of our knowledge, no previous studies have reported the concentration levels of PAEs and BPA in raw urban wastewater in the northern part of the Persian Gulf. Therefore, in this study, the authors aimed to (i) determine the concentration levels, distribution, and sources of PAEs and BPA in untreated urban wastewater entering Bushehr coastal waters, and (ii) conduct an ecological risk assessment of these contaminants in raw wastewater discharged into the Bushehr coastal zone.

Materials and methods

Study area and sampling

Bushehr is a seaside town (28° 92’34’’ N, 50° 82’03’’ E) located in the north of the Persian Gulf and is the third-largest city in the south of Iran, with a total population of about 223,504 in 2017 (Statistical Center of Iran, 2017). Bushehr city suffers from the lack of collection and a proper treatment process of urban wastewater, as well as runoff due to weather conditions and heavy rains in the rainy season. Around 38,000 m³ of municipal wastewater is produced daily in this city. A significant part of the generated wastewater is discharged directly into the sea without any treatment along the beach.

Raw urban wastewater samples were collected from February to April 2023 from six discharge stations along the Bushehr coastline (Fig. 1). A total of 30 samples were collected, with five samples taken from each of the following sites: Shif Island (Station 1), Jofreh Wharf (Station 2), Solh Abad Wharf (Station 3), Siadat Park (Station 4), Jalali Wharf (Station 5), and Rishehr Park (Station 6). All samples were collected in 100 mL pre-cleaned amber glass bottles (Thermo Scientific; cleaned in the laboratory with acetone, hexane and methanol), transported to the laboratory, and filtered through 0.45 μm pore size nylon membrane filters (Whatman) to eliminate suspended particles. The bottles were then covered with aluminum foil and stored at 4 °C until further analysis.

Fig. 1.

The locations of the sampling stations (the map was created using Esri ArcMap, version 10.3, which is available at https://desktop.arcgis.com/en/arcmap/10.0/.).

During the sampling campaign, key physicochemical parameters of the untreated urban wastewater were measured in situ using a multi-parameter probe (Multi 3630 manufactured by WTW (Germany)). These included temperature, pH, and electrical conductivity (EC). The measured values ranged from 26.8 to 31.5 °C for temperature, 7.1 to 7.3 for pH, and 2430 to 3126 µS/cm for EC.

Chemical analysis

PAEs

The extraction protocol for PAEs in seawater samples was adapted from Hajiouni et al.³⁷. Liquid-liquid extraction (LLE) was performed using a separatory funnel. Briefly, 100 mL of filtered seawater was combined with 20 mL of dichloromethane and 20 µL of benzyl benzoate (Merck, Germany) as an internal standard. The mixture was vigorously shaken to facilitate the transfer of PAEs into the organic phase. The organic extract was then transferred into clean glass dishes and sequentially rinsed with dichloromethane, acetone, and n-hexane (all from Merck, Germany) to remove impurities. The cleaned extract was stored at 4 °C until analysis by gas chromatography-mass spectrometry (GC-MS).

PAEs were analyzed using an Agilent 7890 GC/5975 MSD system (USA) equipped with a J&W-5MS ultra inert column (30 m × 0.25 mm I.D., 0.25 mm film thickness).

The GC oven temperature was programmed as follows: initial temperature of 70 °C (held for 1 min), increased to 300 °C at 10 °C/min, and held for 7 min. A 1 µL injection was made using pulsed splitless mode at 290 °C. The helium carrier gas (purity 99.999%) was set at a constant flow of 1 mL/min. Retention times for the analyzed PAEs ranged from 13.4 to 30.4 min for DMP and DOP, respectively. The mass spectrometer’s source and quadrupole temperatures were maintained at 230 °C and 150 °C, respectively. Data were processed using Agilent ChemStation software (E.02.01.1177), and quantification was based on peak areas. The limits of detection (LOD) and quantification (LOQ) ranged from 0.10 to 2.11 ng/L and 0.34 to 6.97 ng/L, respectively. Characteristic ions for quantification included m/z 149 and 163 and retention times of 13.40 to 30.40 min. Table S1 shows precursor and product ions for PAEs analyzed in this study.

BPA

The extraction of BPA was based on protocols from Santhi et al.³⁸. A 100 mL seawater samples was acidified to pH 2–3 using a 1:1 (v/v) nitric acid solution. BPA-d16 (50 ng) was added as an internal standard. Samples were passed through pre-conditioned C18 cartridges. The cartridges were first rinsed with 6 mL of an acetone: hexane (1:1) mixture, followed by 10 mL of methanol and 10 mL of water, each at a flow rate of 1 mL/min. After sample loading (at 4 mL/min), the cartridges were flushed with 6 mL of water and dried under vacuum for 30 min. Elution was performed using four 2.5 mL aliquots of acetone: hexane (1:1), and the eluates were evaporated under nitrogen. The residue was reconstituted in 100 µL of acetone: hexane (1:1), followed by derivatization using 20 µL of N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% Trimethylsilyl (TMS) at 75 °C for 40 min. A 1 µL aliquot was then injected into the GC-MS.

BPA quantification was carried out using an Agilent 7890 GC/5975 MSD (Agilent, USA), following methods from Szyrwinska et al.³⁹ and Al-Saleh et al.⁴⁰. Separation was achieved using an Agilent J&W-5MS ultra-inert column (30 m × 0.25 mm I.D., 0.25 mm film thickness). The temperature program was as follows: initial hold at 80 °C for 2 min, ramping to 285 °C at 8 °C/min, with a final hold of 2 min. Injections were made in pulsed splitless mode with helium as the carrier gas at a constant flow of 1 mL/min. The MS source and quadrupole temperatures were set at 230 °C and 150 °C, respectively, with an interface temperature of 290 °C. BPA was quantified in SIM mode using a target ion of m/z 285 and qualifier ions of m/z 285 and 357 (Table S1). The method showed a recovery of 86.9%, with LOD and LOQ values of 1 ng/L and 3.5 ng/L, respectively.

Additionally, 1 mL of each raw wastewater sample was spiked with 40 µg/L d16-BPA and evaporated at 60 °C. The residue was derivatized with 300 µL of N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) containing 1% Trimethylchlorosilane (TMCS), vortexed, and incubated at 75 °C for 1 h. Samples were then reconstituted in chloroform. Calibration standards (5–160 µg/L) were prepared daily from 1 µg/mL stock solutions of BPA and d16-BPA in methanol. Prior to GC-MS injection, 50 µL of MSTFA was added to the final extract and incubated at 50 °C for 1 h.

Statistical analysis

All statistical analyses were conducted using SPSS version 26.00, and a p-value of ≤ 0.05 was considered significant. For samples with values below the limit of detection (LOD), the amount was set to LOD/2 in the statistical analysis.

Results and discussion

Distribution and occurrence of PAEs and BPA

The composition and levels of individual PAEs in marine environments are crucial for identifying their sources, distribution, and movement⁴¹. The mean concentrations of PAEs in raw urban wastewater from six sampling sites ranged from < LOD to 0.67 µg/L for DMP, 0.29 to 0.92 µg/L for DEP, 0.51 to 1.52 µg/L for DIBP, 0.14 to 0.39 µg/L for DBP, and 19.67 to 39.75 µg/L for DEHP (Table 1). BBP and DOP were below the detection limit at all sites. PAE congeners were detected across all regions, indicating these compounds are prevalent pollutants in the area. The total ΣPAEs concentration ranged from 22.56 to 43.46 µg/L. Notably, the highest PAE levels were found at fishing wharfs (Solh Abad, Jofreh, and Jalali), characterized by significant urban wastewater input, fishing activities, and human presence.

Table 1.

The mean concentration levels of individual PAEs (µg/L) and BPA in Raw urban wastewater collected from six sampling sites (n: 5).

Compounds	Shif Island	Rishehr Park	Jalali Wharf	Jofreh Wharf	Solh Abad Wharf	Siadat Park	p-value	LOD (ng/L)	LOQ (ng/L)
DMP	< LOD	< LOD	0.67	0.38	0.24	0.17	0.041	1.68	5.56
DEP	0.30	0.92	0.29	0.37	0.46	0.50	0.055	0.86	2.84
DIBP	0.51	0.68	1.08	1.20	1.52	1.24	0.002	0.71	2.39
DBP	0.14	0.19	0.33	0.31	0.39	0.39	0.045	0.75	2.46
BBP	< LOD	< LOD	< LOD	< LOD	< LOD	< LOD	0.251	0.10	0.34
DEHP	19.67	30.02	35.12	38.00	39.75	19.84	0.001	1.67	5.50
DOP	< LOD	< LOD	< LOD	< LOD	< LOD	< LOD	0.125	2.11	6.97
ΣPAEs	22.56	33.75	38.59	41.36	43.46	23.24	0.001	-	-
BPA	0.10	2.50	0.56	0.41	0.58	0.63	0.001	1.00	3.50

Figure 2 illustrates the relative contributions of the PAE congeners, with DEHP being the predominant congener across all sampling sites, present in 100% of samples. The average DEHP concentrations were 39.75 ± 4.75 µg/L at Solh Abad Wharf, 38.00 ± 0.50 µg/L at Jofreh Wharf, 35.12 ± 1.28 µg/L at Jalali Wharf, 30.02 ± 0.89 µg/L at Rishehr Park, 19.84 ± 0.95 µg/L at Siadat Park, and 19.67 ± 0.91 µg/L at Shif Island (Table 1). The consistently higher concentrations of DEHP compared to other PAEs can be attributed to its widespread use as a plasticizer in the production of flexible plastics, packaging, and construction materials. These findings are consistent with previous studies identifying DEHP as the most prevalent PAE in municipal and runoff waters^42–45.

Fig. 2.

Relative contributions of the PAEs congeners and BPA in raw wastewater samples of different sites.

For instance, Clara et al.⁴⁵ reported DEHP and DEP as the dominant PAEs in runoff water in Austria. Similarly, Takdastan et al.⁴⁶ detected DEHP in microplastics (MPs) during wastewater treatment, with mean concentrations ranging from 8.13 to 30.081 µg/L. Other studies have confirmed the presence of MPs in untreated urban wastewater^47–50, and several have suggested an association between MPs and PAEs^37,51,52. These relationships imply that plastic debris may act as a vector for PAE contamination through the leaching of additives.

Field observations revealed significant accumulations of plastic debris, particularly near wharves, where wastewater is discharged, primarily from domestic sources. The absence of notable agricultural or industrial inputs suggests that municipal waste and consumer product leachates are the main sources of PAEs in the area⁵³.

Environmental factors such as salinity, temperature, and pH are known to influence the behavior and distribution of PAEs in aquatic systems⁵⁴. The extreme physicochemical conditions of the Persian Gulf— characterized by elevated salinity and temperature— are known to accelerate plastic degradation and contribute to the accumulation of plastic debris^55,56. Pollution by both MPs and PAEs has been reported in various parts of the Persian Gulf^6,41,57, supporting the likelihood that these contaminants originate from multiple environmental matrices, including water, soil, and air.

Pollution by both MPs and PAEs has been reported in various parts of the Persian Gulf^6,41,57, supporting the likelihood that these contaminants originate from multiple environmental matrices, including water, soil, and air.

In addition to PAEs, BPA was detected in all wastewater samples, with concentrations ranging from 0.10 to 2.50 µg/L. The highest concentration was found at Rishehr Park and the lowest at Shif Island, indicating a widespread presence of BPA in urban effluents. Statistical analysis revealed significant spatial differences in BPA concentrations (p < 0.001), likely reflecting variation in local wastewater sources and input intensities. The elevated level at Rishehr Park is attributed to the direct discharge of raw sewage into the coastal water, posing a potential health risk in an area frequently used for recreational swimming. Notably, in August 2022, visible water discoloration led the Bushehr Provincial Environmental Protection Department to declare the site unsafe for public use. In contrast, lower concentrations at Shif Island, a sandy island inhabited by a fishing community, reflect minimal wastewater discharge.

Average BPA concentrations across the sites were as follows: Solh Abad Wharf – 0.58 ± 0.01 µg/L, Jofreh Wharf – 0.41 ± 0.01 µg/L, Jalali Wharf – 0.56 ± 0.02 µg/L, Rishehr Park – 2.50 ± 0.03 µg/L, Siadat Park – 0.63 ± 0.02 µg/L, and Shif Island – 0.10 ± 0.00 µg/L (Table 1). BPA concentrations in untreated wastewater have been widely reported, primarily resulting from the leaching of epoxy resins and polycarbonate plastics^9,58–60. The BPA levels observed in this study are comparable to those observed in wastewater discharges in China^61,62. Wang et al.⁶² reported mean BPA levels of 2.03 µg/L in influents of Chinese WWTPs, and Sun et al.⁶¹ observed concentrations ranging from 189 to 20,400 ng/L (0.189 to 20.4 µg/L) in wastewater samples from Xiamen. Variability in these concentrations often correlates with differences in wastewater sources and industrial activity^63,64.

Other studies from the United States and India report comparatively lower influent BPA levels. For example, Xue and Kannan⁶⁵ reported mean concentrations of 90.0 and 53.3 ng/L in two U.S. treatment plants, while Karthikraj and Kannan⁶⁶ observed a mean of 1.1 ng/L in Indian WWTP influents. The higher concentrations in our study may reflect regional differences in chemical usage, treatment infrastructure, and removal efficiency.

BPA has been detected in a variety of aquatic environments, including rivers, ponds, and marine environments, often in the ng/L range⁶⁷. However, concentrations are typically higher in wastewater discharges due to leaching from plastics and improper disposal^9,58,60. Wastewater effluent is recognized as a major source of BPA in aquatic systems⁶⁸, while discarded plastic debris and land-applied biosolids further contribute to environmental BPA loads.

The detection of both BPA and PAEs in all sampled discharges underscores their pervasive presence in coastal wastewater and highlights their continued input into the marine environment, even in regions with regulatory frameworks targeting these pollutants.

Ecological risk assessment

The presence of PAEs and BPA in aquatic environments raises serious concerns due to their known toxicity to marine life^23,69. These compounds are recognized endocrine disruptors, capable of affecting hormonal regulation, immune responses, gene expression, and behavioral patterns in various marine organisms^11,67. BPA, in particular, has demonstrated endocrine-disrupting effects in amphibians, invertebrates, and fish⁷⁰.

To evaluate the environmental implications of BPA, the concentrations detected in wastewater were compared to the European Union’s predicted no-effect concentration (PNEC) of 1.6 µg/L⁷¹. Except for Rishehr Park, BPA concentrations remained below this threshold, suggesting minimal immediate risk. However, it is important to note that the PNEC does not account for more sensitive organisms, such as mollusks, which may be affected at lower exposure levels⁶⁸. For example, the EC10 for egg production in the freshwater snail Marisa cornuarietis is reported as low as 14.8 ng/L⁷². Thus, even low BPA concentrations in coastal waters may pose ecological threats, especially in areas with chronic exposure⁶⁹. Although the effects of BPA on marine species remain underexplored, additional ecotoxicological data for sensitive taxa are essential for more accurate risk assessments⁶⁷.

In this study, the environmental risks posed by BPA and PAEs were assessed using the risk quotient (RQ) approach, calculated by dividing the measured environmental concentration (MEC) by the PNEC⁷³. MEC values were the concentrations of PAEs and BPA measured in the raw urban wastewater samples, and the PNEC was the predicted no-effect concentration for each compound. The USEPA ECOTOX database was used to evaluate critical/chronic toxicity data for PAEs on sensitive aquatic organisms (e.g., fish, crustaceans, and algae)⁷⁴. The ecological risk was classified into three categories based on RQ values: low risk (RQ < 0.01), medium risk (0.01 < RQ < 1), and high risk (RQ > 1)⁷³. The RQ values of the six PAEs in Persian Gulf water are presented in Table 2. The RQ values followed the order of DEHP > DBP > DEP > DMP. DEHP had RQ values above one in all studied areas (except Shif Island for fish), indicating a considerable risk to sensitive algae, crustaceans, and fish. Similar results were reported in studies of urban runoff along the Persian Gulf coastline³⁷. RQ levels for other congeners were < 0.01, indicating a low risk for sensitive aquatic organisms.

Table 2.

Toxicity data of PAEs and BPA to the most sensitive aquatic species (fish, algae and crustaceans).

PAEs	Non-target organism	NOEC (µg/L)	AF	PNEC (µg/L)	RQ values
					Shif Island	Rishehr Park	Jalali Wharf	Jofreh Wharf	Solh Abad Wharf	Siadat Park
DMP	Algae Crustaceans Fish	10,000 9600 11,000	10 10 10	1000 960 1100	- - -	- - -	0.0007 0.0007 0.0006	0.0004 0.0004 0.0003	0.0002 0.002 0.0002	0.0002 0.0002 0.0001
DEP	Algae Crustaceans Fish	8106 2700 1650	10 10 10	810.6 270 165	0.00037 0.001 0.002	0.001 0.003 0.006	0.0003 0.001 0.002	0.0004 0.001 0.002	0.0006 0.002 0.003	0.0007 0.002 0.003
DIBP	Algae Crustaceans Fish	210 260 100	10 10 10	21 26 10	0.0067 0.005 0.014	0.009 0.007 0.019	0.016 0.012 0.033	0.015 0.01 0.031	0.018 0.015 0.039	0.018 0.015 0.039
BBP	Fish	900	100	90	-	-	-	-	-	-
DEHP	Algae Crustaceans Fish	100 42 300	10 10 10	10 4.24 30	1.97 4.64 0.66	3.00 7.08 1.02	3.50 8.28 1.17	3.80 8.96 1.27	3.97 9.37 1.32	1.98 4.68 0.66
DOP	Crustaceans	34	100	0.34	-	-	-	-	-	-
BPA	Algae	22,000	10	2200	4.5E-05	1.1E-03	2.5E-04	1.9E-04	2.6E-04	2.9E-04
	Daphnia	39,000	10	3900	2.6E-05	6.4E-04	1.4E-04	1.1E-04	1.5E-04	1.6E-04
	Fish	3600	10	3600	2.8E-05	6.9E-04	1.6E-04	1.1E-04	1.6E-04	1.8E-04

NOEC: No observed effect concentration; AF: Assessment factor; PNEC: Predicted no effect concentration.

For BPA, RQ values across all sampling sites were below 0.01, implying a low risk to the related sensitive aquatic species in the studied areas (Table 2). These results are consistent with findings from multi-country assessments, including those in China, Japan, South Korea, and India, where BPA generally posed low to moderate risk in freshwater environments⁶⁹. In certain sections of the Yangtze River, however, RQ values for algae exceeded 0.1, indicating a potential medium risk to sensitive phytoplankton species such as Selenastrum capricornutum⁷⁵.

The results of this study highlight that coastal waters in the northern Persian Gulf, particularly around Bushehr, are under significant ecological pressure from PAEs, especially DEHP. This aligns with findings from southern Thailand, where elevated PAE levels near wastewater outfalls were linked to impaired reproductive and endocrine functions in marine organisms²³. The broader impacts of these pollutants extend to microbial community composition, enzyme activity, and food web dynamics. Given their bioaccumulative nature, PAEs and BPA may also affect higher trophic levels, including humans.

To mitigate these risks, we recommend that wastewater treatment facilities in coastal urban centers like Bushehr incorporate advanced treatment technologies capable of removing endocrine-disrupting compounds. Establishing long-term monitoring programs would facilitate early detection and response to contamination. Additionally, raising public awareness and enforcing stricter regulations on the production, use, and disposal of plastic-related products are crucial steps to reduce the influx of these harmful substances into marine ecosystems.

Conclusion

Urban raw wastewater is an important source of PAEs and BPA in the coastal areas of the Persian Gulf. This study identified significant concentrations of PAEs and BPA in raw wastewater samples from the northern Persian Gulf, especially at sites near human activities and urban wastewater discharges. The mean concentrations of PAEs and BPA in the urban raw wastewater from six selected stations ranged from 22.56 to 43.46 and 0.10 to 2.50 µg/L, respectively. DEHP was the predominant PAE in all areas, and its high RQ values indicate a significant environmental risk to sensitive aquatic organisms. BPA concentrations varied but were below the threshold for significant ecological risk. Our findings suggest that the discharge rate of PAEs from urban surface runoff into the Persian Gulf can be substantial. Since urban wastewater in Bushehr is discharged without treatment, further studies are needed to provide comprehensive data on PAEs and BPA levels in environmental matrices, their exposure, and risk assessments of these endocrine-disrupting chemicals. Additionally, risk assessments are necessary to better understand the health risks associated with seafood consumption. Comprehensive experimental studies can also assess the environmental fate of BPA and other exposure pathways, enable better prediction and understand of potential risks to human and environmental health. Based on our results, it is highly recommended to cease the discharge of materials containing phthalates and BPA into the Bushehr coastline. Bushehr authorities must implement effective policies to prevent further contamination.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

Farshid Soleimani: Methodology, Investigation, Validation, Formal analysis, Resources, Writing– original draft; Mortaza Tavakoli: Supervision, Conceptualization, Project administration; Maryam Ghaemi: Methodology, Investigation, Validation, Supervision, Resources, Conceptualization, Visualization, Writing – review & editing.

Data availability

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Declarations

Competing interests

The authors declare no competing interests.