# Occurrence and concentration of caffeine and cadmium as micropollutants in the Red Sea coast, Egypt

## TL;DR

This study measures caffeine and cadmium levels in the Red Sea coast of Egypt to assess human impact on the environment.

## Contribution

The study provides new data on caffeine and cadmium concentrations in Red Sea coastal areas and their correlation with environmental variables.

## Key findings

- Caffeine concentrations in water ranged from 10.94 to 14.17 µg/L, while in sediment they ranged from 0.27 to 0.66 µg/g.
- Caffeine and cadmium levels varied significantly across sites, reflecting differences in anthropogenic impacts.
- The study found a clear association between caffeine and cadmium concentrations and physicochemical variables.

## Abstract

This study investigated the occurrence and levels of caffeine residue and cadmium traces on the Red Sea coast of Egypt and the effects of environmental variables on caffeine concentration, in order to evaluate the anthropogenic impacts on the coastal area of the Red Sea. To accomplish this study; three different sites were taken: El-Hamraween (HMR), Abo El-Swater (SWT), and Om El-Abas (ABS). Sediment and water samples were collected from low and high intertidal zones during June 2023. Some physicochemical variables and concentrations of caffeine and Cd were measured in the collected samples. Caffeine concentration in water samples ranged from 10.94 to 14.17 µg/L at low intertidal zone in SWT and the high intertidal zone in ABS, respectively, while caffeine concentration in sediment ranged from 0.27 to 0.66 µg/g at low intertidal zone in ABS and the high intertidal zone in HMR, respectively. The results indicate significant differences among the investigated sites according to variations in anthropogenic impacts. This study showed a clear association between caffeine and cadmium concentrations with physicochemical variables. Caffeine and Cd’s correlation and anthropogenic impacts highlight the need for more research on the interactions between pharmaceutical residues and heavy metals and their effects on the environment.

The online version contains supplementary material available at 10.1038/s41598-026-38344-7.