Some heavy metals are harmful and dangerous and cause many risks for food and public health. Also accumulated in fish such as tuna fish as a result of contaminated water or during transport, processing or canning.  The present study was conducted to measure the concentration of some heavy metals (Pb, Cd, Al, Hg, Ni, Co and Cr) in canned tuna of five brands. Materials and Methods: Forty canned tuna samples from five brands were examined to determine their metal concentration. The samples were collected from supermarkets found in Assiut city (Egypt) from June 2017 to November 2017.  The metals were determined using Atomic Absorption Spectrometer Perkin Elymer (Analyst 400) for Pb, Cd, Co, Ni and Cr while Hg was estimated by using ICP (iCAP 6200) and Al was determined using Atomic Absorption Spectrometer (ZEEnit700P). Results: The results revealed that the levels (ppm wet weight) of metals were as following in the examined five brands: (1) Lead: 1.984±0.156 (1.378-2.256), 2.581±0.401 (1.305-3.778), 1.804±0.244 (1.190-2.425), 2.030±0.424 (1.144-3.459), 1.752±0.250 (1.200-2.616) while in total samples was 2.030±0.141 (1.144-3.778). (2) Cadmium: 0.617±0.04 (0.467-0.696), 0.681±0.043 (0.536-0.778), 0.615±0.041 (0.516-0.720), 0.651±0.053 (0.519-0.747), 0.701±0.038 (0.561-0.792) while in total samples was 0.653±0.019 (0.467-0.792). (3) Aluminum: 3.545±0.017 (3.510-3.605), 3.707±0.058 (3.500-3.858), 3.525±0.125 (3.152-3.938), 3.676±0.044 (3.524-3.799), 3.635±0.159 (3.074-4.049), while in total samples was 3.617±0.042 (3.074-4.049). (4) Mercury: 6.640±0.075 (6.385-6.807), 5.105±0.025 (5.039-5.171), 6.823±0.077 (6.611-7.035), 2.948±0.120 (2.615-3.281), 1.745±0.156 (1.301-2.189), while in total samples was 4.652±0.413 (1.301-7.035). (5) Nickel: 2.035±0.148 (1.444-2.202), 1.948±0.155 (1.375-2.302), 1.924±0.159 (1.531-2.250), 1.906±0.215 (1.384-2.352), 1.957±0.127 (1.548-2.283), while in total samples was 1.954±0.067 (1.384-2.352). (6) Cobalt: 1.322±0.149 (0.765-1.656), 1.757±0.082 (1.515-1.957), 2.089±0.165 (1.607-2.525), 2.511±0.123 (2.160-2.785), 2.719±0.110 2.381-3.072), while in total samples was 2.080±0.16 (0.765-3.072). (7) Chromium: 0.246±0.100 (0.000-0.573), 0.039±0.03 (0.000-0.156), ND, ND, 0.030±0.023 (0.000-0.120), while in total samples was 0.063±0.027 (ND-0.573). In this study, the Target Health Quotient (THQ) in the total examined tuna samples was 0.219-0.323 (0.254) for Pb, 0.308-0.351 (0.327) for Cd, 0.00176-0.00185 (0.00181) for Al, 2.913-11.380 (7.757) for Hg, 0.047-0.051 (0.049) for Ni, 0.033-0.049 (0.052) for Co and 0.00001-0.000082 (0.000035) for Cr while the Hazard Health Index (HI)  for all metals was 11.709for brand 1, 9.268 for brand 2, 12.015 for brand 3, 5.604 for brand 4, 3.601for brand 5, all of these are exceeding 1.
Conclusion: The calculated hazard index (HI) in this study in all examined canned tuna in all brands exceeds 1. The data indicate that the examined canned tuna were polluted with Pb, Cd, Al, Hg and Ni. Hazard indices for the estimated metals in these canned tuna imply that excessive and continuous intake of these tuna could result in chronic adverse health effects on the consumers. However, consumption of large quantities of these canned tuna increases human exposure to the risk especially of Hg toxicity. Recommendation: It recommended that more studies for assessment for quality control should be done to help safeguard the health consumers.