Penentuan Tahap Logam Berat, Hafazan Al-Quran dan Kecerdasan (IQ) dalam Kalangan Pelajar Tahfiz di Selangor.

Tahfiz school is an institution that specialises in educating students to memorize and recite the whole al-Quran. Memorizing the al-Quran by rote learning will activate the brain to improve the brain ability to process, store information and build memory. The presence of heavy metals affects the nervous system and interferes with the function of the central and peripheral nervous system which will then cause the impairment of mental and cognitive function. The ability to learn, remember or memorize, use of language and to understand something may be disrupted and cause small decrease in IQ and attention. A cross-sectional study was conducted to measure and to determine the correlation between the levels of heavy metals, al-Quran memorization and intelligence (IQ) among students in selected tahfiz schools compared to nontahfiz schools in Selangor. Levels of heavy metals in nail and hair samples were analyzed by using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Wechsler Abbreviated Intelligence Scale Revised (WASI-II) test for intelligence was used to measure the student's IQ. Questionnaires were used used to obtain demographic data and was analyzed by using the SPSS version 23.0. Based on the Pearson correlation test, there was a very weak negative correlation and significant relationship between manganese in the hair samples with the level of al-Quran memorization (r = -0.178, p = 0.017). In addition, there was a weak positive correlation but significant relationship between the level of intelligence (IQ) with the level of al-Quran memorization (r = 0.375, p = < 0.001). As a conclusion, the higher the concentration of manganese is associated with a decline in the level of al-Quran memorization and the higher the level of al-Quran memorization is related with increase in the level of intelligence (IQ). [ABSTRACT FROM AUTHOR]