The effects of plastic additives on swimming activity and startle response in marine amphipod Echinogammarus marinus.

Plastic additives are widely used in plastic production and are found in the environment owing to their widespread applications. Among these additives, N-butyl benzenesulfonamide (NBBS) and triphenyl phosphate (TPHP) are under international watchlist for evaluation, with limited studies on amphipods. Di-ethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP) are banned in some countries and categorised as substances of very high concern. This study aimed to investigate the effects of NBBS, TPHP, DEHP and DBP on the swimming activity of a coastal intertidal marine amphipod, Echinogammarus marinus. Furthermore, this study is the first to quantify startle response in E. marinus in response to light stimuli. Amphipods were exposed to 0, 0.5, 5, 50 and 500 µg/l concentrations of all test compounds. Swimming activity and startle responses were assessed by video tracking and analysis using an 8-min alternating dark and light protocol after exposure on days 7 and 14. We observed an overall compound and light effect on the swimming activity of E. marinus. A significant decrease in swimming distance was found in 500 µg/l NBBS and TPHP. We observed that the startle response in E. marinus had a latency period of >2 s and animals were assessed at 1 s and the sum of the first 5 s. There was a clear startle response in E. marinus during dark to light transition, evident with increased swimming distance. NBBS exposure significantly increased startle response at environmental concentrations, while significant effects were only seen in 500 µg/l TPHP at 5 s. We found no significant effects of DEHP and DBP on swimming behaviour at the concentrations assessed. The findings of this study affirm the necessity for a continuous review of plastic additives to combat adverse behavioural effects that may be transferable to the population levels.

Polycyclic Aromatic Hydrocarbons in Ologe Lagoon and Effects of Benzo[b]fluoranthene in African Catfish.

BACKGROUND: Ologe Lagoon is an important water body that receives effluents from neighboring industries. These effluents may increase the levels of anthropogenic contaminants in the lagoon, thereby creating stressors for aquatic organisms. OBJECTIVES: To assess the occurrence of polycyclic aromatic hydrocarbons (PAHs) in Ologe Lagoon, along with the histopathological, biochemical and genotoxic effects of the most prevalent PAH compound. METHODS: An initial field study was performed to determine the concentrations of PAHs in Ologe Lagoon, followed by a chronic toxicity test to assess the effects of the most prevalent PAH compound in a fish model (Clarias gariepinus). RESULTS: High molecular weight PAHs were more predominant than low molecular weight PAHs in the lagoon, with B[b]F being the most predominant. The formation of micronuclei and binuclei was induced by a 10-fold increase over the present environmental concentration of B[b]F in Ologe Lagoon. Histopathological studies showed that epithelial necrosis, fused lamellae, shortened lamellae, and desquamation were the major histological anomalies induced by ERCs of B[b]F. Results from the biochemical assay indicated that ERCs of B[b] F increased aspartate aminotransferase and alanine transaminase levels in fish. Glutathione-S-transferase, superoxide dismutase and catalase were inhibited in the exposed fish, whereas malondialdehyde was significantly increased. CONCLUSIONS: Concentrations of fluoranthene, pyrene, benzo[a]anthracene, and benzo[a] pyrene in the surface water of Ologe Lagoon were above the Canadian Council of Ministers of the Environment's (CCME) safe limits, suggesting that the water may not be safe for domestic uses, and the present concentration of B[b]F in Ologe Lagoon may be chronically toxic to aquatic organisms, in terms of oxidative stress and hepatotoxicity. COMPETING INTERESTS: The authors declare no competing financial interests.

Air Pollution Monitoring Around Residential and Transportation Sector Locations in Lagos Mainland.

BACKGROUND: Industrialization and urbanization, while associated with increased productivity, are also potential causes of increased air pollution. Urban air quality has the potential to affect the health and wellbeing of residents of urban areas. OBJECTIVES: The present study investigated the levels of air pollutants around residential areas and transport sector locations (TSLs) in Lagos, Nigeria. Residential areas were defined as areas around inner streets and living quarters, while TSLs included busy roads, dual carriage roads, bus stops and major car parks in the Yaba Local Council Development Area of Lagos Mainland, Lagos, Nigeria. METHODS: Air quality parameters were assessed in situ using calibrated hand-held devices at selected residential and TSLs. Each sampling location was geo-referenced and concentrations of the various parameters were used to plot distribution maps. RESULTS: The findings from the monitoring exercise showed that levels of the measured air pollutants: carbon monoxide (CO), particulate matter (PM10 and PM2.5), sulphur dioxide (SO2), noise, temperature and humidity were within the ranges of 1.00 - 6.0 5.97 ppm, 43.345.2 - 127.2159.7 µg/m3, 20.3 23.25 - 69.058.16 µg/m3, 0.0 0 - 0.20.17 ppm, 47.7 50 - 65 70.1 dB, 26.2227.2 - 35.536.7°C and 57.0157.6 - 91.8492.3%, respectively, around residential areas. Values of the measured air pollutants at the TSLs ranged as follows: 2.011.0 - 5.397.7 ppm, 103.3360.7 - 179.77404.0 µg/m3, 50.2832.3 - 91.01184.0 µg/m3, 0.00 - 0.40 ppm, 64.2153.1 - 71.1376.3 dB, 27.1826.2 -27.9332.6°C and 60.3660.0 - 75.0178.0%, respectively. Hydrogen sulphide (H2S), ammonia (NH3), nitrogen oxide (NO2) were below detection limits in both sampling locations while volatile organic carbons (VOCs) ranged from 0.00 - 0.10 ppm in the TSLs. DISCUSSION: Most assessed air quality parameters were significantly higher around bus stops (P < 0.05), except for CO and humidity. In addition, PM10 and PM2.5 were much higher than the World Health Organization (WHO) guidelines. The results indicated that the quality of air (particulate matter) in the study area was poor, especially in the TSLs. CONCLUSIONS: The Federal Ministry of Environment, through its relevant agencies, must create policies to address urban air pollution, taking into consideration long term exposures and people that are most vulnerable within the population. COMPETING INTERESTS: The authors declare no competing financial interests.