Arsenic is a carcinogen element that occurs naturally in our environment. Humans can be exposed to arsenic through ingestion, inhalation, and dermal absorption. However, the most significant exposure pathway is via oral ingestion. Therefore, a comparative cross-sectional study was conducted to determine the local arsenic concentration in drinking water and hair. Then, the prevalence of arsenicosis was evaluated to assess the presence of the disease in the community. The study was conducted in two villages, namely Village AG and Village P, in Perak, Malaysia. Socio-demographic data, water consumption patterns, medical history, and signs and symptoms of arsenic poisoning were obtained using questionnaires. In addition, physical examinations by medical doctors were performed to confirm the signs reported by the respondents. A total of 395 drinking water samples and 639 hair samples were collected from both villages. The samples were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) to determine arsenic concentration. The results showed that 41% of water samples from Village AG contained arsenic concentrations of more than 0.01 mg/L. In contrast, none of the water samples from Village P exceeded this level. Whilst, for hair samples, 85 (13.5%) of total respondents had arsenic levels above 1 μg/g. A total of 18 respondents in Village AG had at least one sign of arsenicosis and hair arsenic levels of more than 1 μg/g. Factors significantly associated with increased arsenic levels in hair were female, increasing age, living in Village AG and smoking. The prevalence of arsenicosis in the exposed village indicates chronic arsenic exposure, and immediate mitigation action needs to be taken to ensure the wellbeing of the residents in the exposed village.

Introduction Environmental tobacco smoke (ETS) is generally known as secondhand smoke. Assessing the magnitude of children’s exposure to ETS from early infancy is essential for public health and research endeavours. Urinary cotinine is now widely recognised as the primary indicator for assessing exposure to ETS across all age groups. This systematic review and meta-analysis aim to synthesise all the published evidence on the urinary cotinine cut-off concentrations used to categorise children under 5 years as being exposed to ETS. Methods and analysis We will conduct a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A comprehensive search will be conducted from various databases including PubMed, EMBASE, Scopus and Cochrane Library. This search will be performed from the earliest published articles up to the latest available studies until February 2025. We will include all the experimental and observational studies, such as cohort, case–control and cross-sectional, that measure urinary cotinine concentrations in children under 5 years old. Data extraction will be conducted using a standardised data extraction form, and the study quality will be evaluated according to the guidelines specified by the Newcastle-Ottawa Scale. The extracted data will be pooled and combined for meta-analysis. Two reviewers will independently screen, select and assess the quality of the included study. The result will be tabulated in a table of characteristics of the included study, which consists of the cut-off cotinine concentrations, analytical technique, method referred, study design, study area and respondents’ characteristics. Ethics and dissemination Ethics approval is not required as this is a review of collected published data. Findings will be disseminated in peer-reviewed publications and conference presentations, as well as with key stakeholders, health policymakers and healthcare professionals. PROSPERO registration number CRD42024556969.

Cephalopods and crustaceans are known to bioaccumulate heavy metals, potentially posing both non-carcinogenic and carcinogenic health risks to consumers. This study was conducted to determine heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples. Heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples collected from selected wholesale markets and major fish landing ports throughout Peninsular Malaysia. The analysis focused on nine heavy metals: selenium (Se), cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), antimony (Sb), tin (Sn), chromium (Cr), and manganese (Mn). The samples were digested using a microwave digestion system, and heavy metal concentrations were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results showed that Mn was the most abundant metal, followed by Cr and Zn. Octopus (C. indicus) had the highest Mn concentration (5.01 mg/kg WW), while Rainbow shrimp (P. sculptilis) had the highest overall metal concentration (91.02 mg/kg WW). Significant differences were observed between cephalopods and crustaceans, with Cd and Sn concentrations being notably higher in cephalopods (p < 0.001). However, no significant associations were observed between heavy metal concentrations and sample weight or length, indicating a greater influence of environmental factors. Principal Component Analysis (PCA) explained 80.4% of the variance, with Cd, Sn, Pb, Cu, Zn, Cr, and Mn accounting for the majority of the variance. Estimated weekly intake (EWI) values ranged from 0.002 to 26.30 µg/kg bw/week for cephalopods and 8.02 × 10⁻⁶ to 243.175 µg/kg bw/week for crustaceans. All metal levels were below the permissible limits set by the Food and Agriculture Organisation of the United Nations/World Health Organisation (FAO/WHO). Hazard Index values were <1, indicating low non-carcinogenic risk, and Total Carcinogenic Risk values for Pb and Cr were below 1 × 10⁻⁴, suggesting negligible carcinogenic risk.

Prolonged exposure to fine particulate matter (PM2.5), which is less than 2.5 micrometers in diameter, has been linked to significant health risks, including increased mortality from cardiopulmonary diseases and lung cancer. Developing effective local-level forecasting models is crucial, as these models allow authorities and the public to anticipate and respond to unhealthy air quality conditions. This study aims to develop Multiple Linear Regression (MLR) models to estimate PM2.5 concentrations diurnally across nine different locations in the Greater Klang Valley (GKV) and to examine the influence of meteorological factors, namely temperature and humidity. Model validation using ground-based data yielded R-squared values ranging from 0.3558 to 0.7188 and RMSE values from 0.093 to 1.7687, indicating that temperature and humidity significantly affect PM2.5 levels. Additionally, a correlation analysis between Landsat 8 satellite data and ground-based PM2.5 measurements revealed that Band 8 had the highest correlation coefficient of 0.574, with an R-squared value of 0.329 and a highly significant p-value of 0.005. Spatial distribution map of PM2.5. temperature and humidity have been generated and it showed that PM2.5 levels were lower in northern GKV from July to December 2022 but increased across central and southern regions in early 2023, especially between February and May. These patterns indicate seasonal variation and suggest that higher temperatures and lower humidity may influence pollutant concentration.